gh-3153 fixing flaky test shouldConstructGraphAndCreateViewWithGroups

[omkrpt]

What is the purpose of this PR

• Linked issue
• This PR fixes the flaky test: uk.gov.gchq.gaffer.graph.GraphTest#shouldConstructGraphAndCreateViewWithGroups
• The test may fail or pass without changes made to the source code when it is run in different JVMs due to the non-deterministic ordering when sets are converted to arrays.

Why the test fails

• The assertions at L925-L926 in this test compare the keys of Map objects with the keySet of Maps in resultView.
• However, while invoking the java.util.Map.keySet() is necessary for comparison, the second conversion by calling java.util.Set.toArray() returns the elements in a non-deterministic order.

How to reproduce the test failure

I used a tool called nondex.

mvn install -pl core/graph -am -DskipTests
mvn -pl core/graph test -Dtest=uk.gov.gchq.gaffer.graph.GraphTest#shouldConstructGraphAndCreateViewWithGroups
mvn -pl core/graph edu.illinois:nondex-maven-plugin:2.1.1:nondex -Dtest=uk.gov.gchq.gaffer.graph.GraphTest#shouldConstructGraphAndCreateViewWithGroups

Expected results

• The test should run successfully when run with NonDex.

Actual results We get the following failures:

[ERROR] Tests run: 1, Failures: 1, Errors: 0, Skipped: 0, Time elapsed: 0.551 s <<< FAILURE! -- in uk.gov.gchq.gaffer.graph.GraphTest
[ERROR] uk.gov.gchq.gaffer.graph.GraphTest.shouldConstructGraphAndCreateViewWithGroups(Store) -- Time elapsed: 0.537 s <<< FAILURE!
org.opentest4j.AssertionFailedError: array contents differ at index [0], expected: <entity2> but was: <entity3>
    at org.junit.jupiter.api.AssertionFailureBuilder.build(AssertionFailureBuilder.java:151)
    at org.junit.jupiter.api.AssertionFailureBuilder.buildAndThrow(AssertionFailureBuilder.java:132)
    at org.junit.jupiter.api.AssertArrayEquals.failArraysNotEqual(AssertArrayEquals.java:440)
    at org.junit.jupiter.api.AssertArrayEquals.assertArrayElementsEqual(AssertArrayEquals.java:389)
    at org.junit.jupiter.api.AssertArrayEquals.assertArrayEquals(AssertArrayEquals.java:346)
    at org.junit.jupiter.api.AssertArrayEquals.assertArrayEquals(AssertArrayEquals.java:159)
    at org.junit.jupiter.api.AssertArrayEquals.assertArrayEquals(AssertArrayEquals.java:155)
    at org.junit.jupiter.api.Assertions.assertArrayEquals(Assertions.java:1453)
    at uk.gov.gchq.gaffer.graph.GraphTest.shouldConstructGraphAndCreateViewWithGroups(GraphTest.java:925)
...

Description of fix Comparing the sets directly, without converting them to arrays.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Comparison is base (ac60289) 66.34% compared to head (3472917) 66.33%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## develop #3155 +/- ## ============================================= - Coverage 66.34% 66.33% -0.02% + Complexity 2543 2541 -2 ============================================= Files 909 909 Lines 29026 29026 Branches 3225 3225 ============================================= - Hits 19257 19253 -4 - Misses 8333 8335 +2 - Partials 1436 1438 +2 ```

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