Transcript ArchitecturalStyles

Architectural Styles
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Team
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Interpreter; event driven
Peer-to-peer; plug-in
Service-oriented; publish-subscribe
Rule-based; mobile code
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Team Onesies:
Jaime Pena, Carlos Montijo
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◦ What is it?
◦ What problem does it solve?
◦ How does it solve the problem?
◦ Who are the actors or main elements?
◦ How do they relate to each other?
◦ What are the strengths and drawbacks?
◦ Example applications?
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Takes a program written in one language and
interprets it to another language to execute a
series of commands
Also known as Virtual Machine Style
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Facilitates coding in high level language,
which can be interpreted into lower level
language
Interpreter can be used in different machines
Suitable for applications in which most
appropriate language or machine for
executing solution is not directly available
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Interpreter translates programming language
for the user without requiring user to know
the language
Interpreter allows for portability
Code interpreted in one machine will execute
the same in another
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Interpreter Engine
◦ receives input and generates output
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Interpreter State
◦ state of interpreter engine
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Program State
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Data Store Field
◦ progress of code interpreted
◦ source code
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Input to the interpreted program component
is sent to the program state, where it is read
by the program running on the interpreter
Program output is placed in the program
state, where it can result in output from the
interpreted program component's interface
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Advantages
Portability and
flexibility of
application or
languages across
various platforms
Supports dynamic
change
“Sandbox” safety
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Disadvantages
Slow
Hard to design and
test
Cannot generate all
possible programs
to be executed
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Java, Java Virtual Machine (JVM)
Python-based applications
Lisp
Perl
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Team Onesies:
Alexandra Rebollosa, Achim Schweighofer, Heber Ramirez
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A framework that orchestrates behavior around the
production, detection and consumption of events as
well as the responses they evoke
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Request/Response pattern
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Consists of “event creators” and “event consumers”
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Event: Any identifiable occurrence that has significance for
system hardware/software
Creator: Source of the event, only knows the event has
occurred
Consumer: Entity that needs to know the event has occurred,
they might be involved in processing the event or they might
simply be affected by the event
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Real-time analysis of data and response of
system
Takes care of discrepancies in the system by
following step-by-step rules
◦ E.g., when buying online using Amazon, a login is
required in order to complete an order. If the
customer is not a registered user, a new user must
be created
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It enables a large number of creators and
consumers to exchange status and response
information in near real-time.
Most effective when existing business rules,
triggers, and related stored procedures are
surfaced and made available to the middleware’s
event processor.
In the short run, this means additional work for the
database administrator.In the long run, it simplifies
data management by making changes easier.
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Event Generator
◦ Detects an event
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Event Channel
◦ Entry point to function, TCP/IP-Connection, File …
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Event Processing Engine
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Downstream Event-Driven Activity
◦ Selection of appropriate reaction
◦ Reaction to event
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Event generator senses facts and converts the
collected data into a standardized form
The collected data is transferred over event
channels to event engine (asynchronously)
Event processing identifies the event, selects
and executes the appropriate reaction
 Downstream event-driven activity
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Advantages
Strong support for
reuse.
Adding and
replacing
components with
minimum effect on
other components
in the system.
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Disadvantages
Loss of control, for
example, in which
order will
components be
evoked?
Correctness hard to
ensure since it
depends on order
of invocation.
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Java Swing API
JavaScript
WinForms API
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1.
http://books.google.com/books?id=WHMksQOj6ScC&pg=PA76&lpg=PA76&dq=interpreter+
software+architecture&source=bl&ots=Wz3582xfgT&sig=E18v3bzd0LMGcKGHQynBW5Y5dh
0&hl=en&sa=X&ei=waMoT4CBCuiU2AWOy83iAg&ved=0CHcQ6AEwCA#v=onepage&q=interp
reter%20software%20architecture&f=false
2.
http://etd.lsu.edu/docs/available/etd-07082004-152330/unrestricted/Banerjee_thesis.pdf
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http://www.thomasalspaugh.org/pub/fnd/architecture.html#Interpreter
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5.
http://cs.queensu.ca/~ahmed/home/teaching/CISC322/F09/slides/CISC322_03_Architectur
eStyles.pdf
https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=4&ved=0CFUQFjAD&
url=http%3A%2F%2Fwww.courses.utep.edu%2FPortals%2F870%2Ff11s12%2520handouts%2FSlides%2FL04b%2520More%2520Software%2520Architectures.pptx&ei=EEYuUqnhGaacygHwvoHwBQ&usg=A
FQjCNGxOvLMOaUHiBd6duOo46mlx5BbBw&sig2=bnzA9WbAGiwme8hbIiGemA&bvm=bv.517
73540,d.aWc&cad=rja
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http://se.inf.ethz.ch/courses/2011a_spring/soft_arch/lectures/14_softarch_styles.pdf
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http://kristiannissen.wordpress.com/2009/10/15/javascript-event-driven-architecture/
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http://en.wikipedia.org/wiki/Event-driven_architecture
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http://www.omg.org/soa/Uploaded%20Docs/EDA/bda2-2-06cc.pdf
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http://searchsoa.techtarget.com/definition/event-driven-architecture
11.
http://msdn.microsoft.com/en-us/architecture/aa699424.aspx
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Team 2
Monica Galindo
Andrea Dominguez
Berenice Olivas
Steven Werner
Carlos Luevanos
Daniel Guzman
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Type of decentralized and distributed network
architecture in which individual nodes in the
network (called "peers") act as both suppliers and
consumers of resources.
(http://en.wikipedia.org/wiki/Peer-to-peer)
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The P2P style allows the client and server to swap
their roles in order to distribute and synchronize
files and information across multiple clients. It
extends the client/server style through multiple
responses to requests, shared data, resource
discovery, and resilience to removal of peers.
(http://msdn.microsoft.com/en-us/library/ee658117.aspx)
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They solve the client-server problem where
client nodes request access to resources
provided by central servers.
No need for centralized coordination from
servers
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By allowing peers to make their resources
available to other network participants
Resources such as processing power, disk
storage or network bandwidth
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Peers: independent components, having their own
state and control thread.
Connectors: Network protocols, often custom.
Data Elements: Network messages
Topology: Network (may have redundant connections
between peers); can vary arbitrarily and dynamically
Supports: decentralized computing with flow of
control and resources distributed among peers.
Highly robust in the face of failure of any given node.
• Caution: Scalable in terms of access to resources and
computing power. But caution on the protocol.
(csse.usc.edu/classes/cs578_2013/Styles.ppt)
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They relate to each other by sharing all their
components i.e processors
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It is easy to install and so is the configuration of computers on
this network.
All the resources and contents are shared by all the peers,
unlike server-client architecture where server shares all the
contents and resources.
P2P is more reliable as central dependency is eliminated.
Failure of one peer doesn’t affect the functioning of other
peers. In case of Client –Server network, if server goes down
whole network gets affected.
There is no need for full-time System Administrator. Every
user is the administrator of his machine. User can control their
shared resources.
The over-all cost of building and maintaining this type of
network is comparatively very less.
http://www.ianswer4u.com/2011/05/peer-to-peer-networkp2p-advantages-and.html#axzz2ePzeqMIW
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In this network, the whole system is decentralized thus it is
difficult to administer. That is one person cannot determine the
whole accessibility setting of whole network.
Security in this system is very less. Viruses, spywares, trojans,
and malwares can easily be transmitted over this P2P
architecture.
Data recovery or backup is very difficult. Each computer should
have its own back-up system.
Lot of movies, music and other copyrighted files are transferred
using this type of file transfer. P2P is the technology used in
torrents.
http://www.ianswer4u.com/2011/05/peer-to-peer-network-p2p-advantagesand.html#axzz2ePzeqMIW
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Distribution of copyrighted files.
Security issues.
Bandwidth consumption.
http://www.slideshare.net/srijish/p2p-principle-architecture-and-challenges-presentation
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Fault Tolerance: Decentralized logical
networks which could support any type of
data.
BitTorrent: P2P file sharing protocols. It
accounts for a significant amount of traffic on
the Internet.
Peercasting: Like broadcasting. Method of
streaming content to consumers.
http://p2peducation.pbworks.com/w/page/8897427/FrontPage
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Structural version:
Futuristic Vertical City Holds
Plug-In Hexagonal Housing Units
Software version:
We currently use all the time…
[1]
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A plug in is a
software
component that
adds a specific
feature to an
existing software
application
Works as a puzzle
piece, adding to
the big picture, not
changing it
[2]
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to enable third-party developers to create
abilities which extend an application
to support easily adding new features
to reduce the size of an application
to separate source code from an application
because of incompatible software licenses.
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Many, even unknown ones…
◦ Adding functionality for specific purpose
 Examples: OneTab for Chrome Browser
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Firefox
[3]
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Word
[4]
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Provides framework for developers to add
features
Does not require source code to do it
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Separate valid plug-in modules
◦ Implemented independently
◦ Usually one function/focus
◦ Contribute functionality to many applications that
fit the architecture
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Host Application
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Each plug-in has a well defined interface
Host application must define a plug-in
architecture
Plug-in fits like a piece to a puzzle
(application)
Abstract base class (principle class) included
as part of plug-in bundle
◦ Support code and resources
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Host application checks if it conforms to
requirements
◦ If yes, then an instance is generated
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Expandability
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◦ Poor interface design
restricting extension
◦ Include new features
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Parallel Development
◦ Multiple features can be
developed simultaneously
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Clear Development
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Simplicity
◦ Plugin typically only does
one thing
Strengths
Maintainability
◦ Managing backward
compatibility
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Complexity
◦ Plugin interactions cause
bugs
◦ Well defined interface
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Extensibility
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Testing
◦ Cumbersome without
mock plugin runner
Weaknesses
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http://www.slideshare.net/srijish/p2p-principlearchitecture-and-challenges-presentation
http://www.ianswer4u.com/2011/05/peer-topeer-network-p2p-advantagesand.html#axzz2ePzeqMIW
http://msdn.microsoft.com/enus/library/ee658117.aspx
csse.usc.edu/classes/cs578_2013/Styles.ppt
http://www.dmst.aueb.gr/dds/pubs/jrnl/2004ACMCS-p2p/html/AS04.html
http://p2peducation.pbworks.com/w/page/8897
427/FrontPage
(http://en.wikipedia.org/wiki/Peer-to-peer)
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Images:
◦ [1] http://inhabitat.com/plug-your-hexagonal-house-into-thisvertical-city/
◦ [2] https://developer.apple.com/library/mac/documentation
/Cocoa/Conceptual/LoadingCode/Concepts/Plugins.html
◦ [3] https://addons.mozilla.org/en-US/firefox/
◦ [4] http://msdn.microsoft.com/en-us/library/office/
◦ aa189710(v=office.10).aspx
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References
◦ http://stackoverflow.com/questions/2818415/what-are-the-advantages-anddisadvantages-of-plug-in-based-architecture
◦ https://developer.apple.com/library/mac/documentation/Cocoa/Conceptual/Loadin
gCode/Concepts/Plugins.html
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Publish-Subscriber Style
Service-Oriented Style
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Message pattern
where senders of the
messages (publishers)
do not program the
messages to be sent
directly to a specific
receiver (subscribers).
 the message will be
seen by a
subscriber once they
have subscribed to
the publisher
What?
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publishers don’t
have to know who
the subscribers are
subscribers will only
have information of
subscribers that
they are interested
with
Why?
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How: This architecture uses filtering in order to ensure
that only certain information is delivered to specific users
Actors:
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Actor Relations:
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◦ Publisher
◦ Event Channel
◦ Subscriber
◦ Subscribers choose which publisher they wish to receive
information for
◦ Publishers publish an even to a “channel”
◦ The channel receives information of subscribers as well as
publishers allowing the subscriber to receive pertinent
information from the chosen publisher
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scalability, through clever
protocols the
publisher/subscriber pattern
allows for higher message
loads from a small number of
data center
This favors scalability
through parallel operations,
and tree or network based
routing
by not being dependent on
each other they can work
independently despite the
state of the others.
Strength
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The pattern must be
carefully coded to allow
certain features like
guaranteed delivery of
messages
There may be an assumption
of an audience when one may
not be present
Loose Coupling is also a
disadvantage because it is
hard to guarantee outcomes
since the publisher has little
information from subscribers
Drawbacks
Examples: RSS Feeds, YouTube
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Computing based on
request and reply.
 Provides application
functionality as service.
 Allow easy cooperation
of a large number of
computers that are
connected over a
network.
 Modules driven
implementation. It gives
the ability to develop
What?
new functions rapidly.
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Improved information
flow.
Organizational flexibility.
Lower software
development and
management costs. (reuse).
Security attacks.
Data confidentiality and
integrity.
Maintenance and upgrade.
Reliability.
Why?
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How:
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Actors:
This architecture takes advantage of previously defined services
in order to promote re-usability as well as quick delivery of services
◦ Service provider,
◦ Service directory (registry),
◦ Service consumer
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Actor Relations:
◦ The service provider publishes and secures the service in
a service directory.
◦ The service consumer locates and accesses the service in
the service directory.
◦ The service consumer manages the service provided by
the service provider.
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◦ Service can be re-used.
◦ Messaging: control, monitoring,
transformation, security.
◦ Complex event processing
(ability to adapt)
◦ service discovery
◦ Virtualization (improved
reliability)
◦ Model-driven implementation.
◦ Easy maintenance.
◦ Loose Coupling
◦ Overhead
◦ Complexity
◦ Configuration
management
◦ Governance
◦ Hard to implement
when starts at zero.
Examples: TurboTax, Wells Fargo, Cricket
wireless,
Strengths
Drawbacks
Facebook, Dropbox
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Birman, K. and Joseph, T. "Exploiting virtual
synchrony in distributed systems" in Proceedings
of the eleventh ACM Symposium on Operating
systems principles (SOSP '87), 1987
Hasan, Souleiman, Sean O'Riain, and Edward
Curry. 2012. "Approximate Semantic Matching of
Heterogeneous Events.“
http://msdn.microsoft.com/enus/magazine/hh201955.aspx
http://en.wikipedia.org/wiki/Publish%E2%80%93s
ubscribe_pattern
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http://searchsoa.techtarget.com/definition/s
ervice-oriented-architecture
http://www.javaworld.com/javaworld/jw-062005/jw-0613-soa.html
http://www.opengroup.org/soa/sourcebook/soa/soa_features.html
www.exforsys.com
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Software that can duplicate human knowledge
and reason from it.
A collection of knowledge, which can be a set
of rules.
Database of facts
Based on Condition-Action Rules
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Shortage of experts.
◦ Duplicating expert reasoning quickly.
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User Interface
Rule Engine
Inference
Engine
Process
Working
Memory
Temporary
Data
Rule Base
Permanent Data
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Strengths
◦ Knowledge of experts can be duplicated.
◦ Can be adapted to many different fields.
◦ Easy for humans to understand
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Drawbacks
◦ Can only be used were knowledge can be describe
as an If-Then statement.
◦ The larger the number of statements the slower the
system will perform.
◦ Is it possible to capture all knowledge?
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AI
Voice Server
Health Care
Financial Service.
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Code is portable since it can run anywhere
No installation
load on server is reduced, since the code is
run on client machine
interoperability
user unaware that mobile code is executing
on their machine
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java applets
activeX controls
macros in MS office
scripts
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"Mobile Code." Mobile Code. 11 Sept. 2013
<http://courses.ischool.berkeley.edu/i206/f97/
GroupC/sld003.htm>.
"Mobile Code Security." Mobile Code Security. 11
Sept. 2013
<http://seit.unsw.adfa.edu.au/staff/sites/lpb/pa
pers/mcode96.html>.
Ireson-Paine, Jocelyn. "What is a rule-based
system?" What is a rule-based system? 14 Feb.
1996. 11 Sept. 2013 <http://www.jpaine.org/students/lectures/lect3/node5.html>.
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