Refactor dispute agent selection.

[ghost]

• Dispute agent can be chosen randomly.
• Eliminates internal dependencies, simplifies code.

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Tests output:

ArbitratorSelectionTest > testGetRandomArbitratorFromThree() STANDARD_OUT

testArbitratorSelection with 3 arbitrators 10000 iterations, expected percentage=0.333333
arb=arb2 result=3339 percentage=0.333900
arb=arb1 result=3262 percentage=0.326200
arb=arb3 result=3399 percentage=0.339900

ArbitratorSelectionTest > testGetRandomArbitratorFromFour() STANDARD_OUT

testArbitratorSelection with 4 arbitrators 1000 iterations, expected percentage=0.250000
arb=arb2 result=236 percentage=0.236000
arb=arb1 result=243 percentage=0.243000
arb=arb4 result=267 percentage=0.267000
arb=arb3 result=254 percentage=0.254000

ArbitratorSelectionTest > testGetRandomArbitratorFromOne() STANDARD_OUT

testArbitratorSelection with 1 arbitrators 10 iterations, expected percentage=1.000000
arb=arb1 result=10 percentage=1.000000

ArbitratorSelectionTest > testGetRandomArbitratorFromTwo() STANDARD_OUT

testArbitratorSelection with 2 arbitrators 10000 iterations, expected percentage=0.500000
arb=arb2 result=5060 percentage=0.506000
arb=arb1 result=4940 percentage=0.494000

[alvasw]

Nit
Looks good!

Here are some suggestions:
We only need to iterate once over the disputeAgentManager.getObservableMap() by using Collections.shuffle(disputeAgents). Furthermore, we can use getRandomMediator in the tests and get rid of the getRandomDisputeAgent method. I pushed an example to my repository. See: alvasw@ddfae00

[alvasw]

ACK

[alejandrogarcia83]

utACK