NPE in ClaimReplicationQueuesProcedure when running TestAssignmentManager.testAssignSocketTimeout

2023-05-03T05:56:10,094 ERROR [PEWorker-18 {}] procedure2.ProcedureExecutor(1669): CODE-BUG: Uncaught runtime exception: pid=8, ppid=5, state=RUNNABLE, hasLock=true; org.apache.hadoop.hbase.master.replication.ClaimReplicationQueuesProcedure
java.lang.NullPointerException: null
at org.apache.hadoop.hbase.master.replication.ClaimReplicationQueuesProcedure.execute(ClaimReplicationQueuesProcedure.java:83) ~[classes/:?]
at org.apache.hadoop.hbase.master.replication.ClaimReplicationQueuesProcedure.execute(ClaimReplicationQueuesProcedure.java:48) ~[classes/:?]
at org.apache.hadoop.hbase.procedure2.Procedure.doExecute(Procedure.java:919) ~[hbase-procedure-3.0.0-alpha-4-SNAPSHOT.jar:3.0.0-alpha-4-SNAPSHOT]
at org.apache.hadoop.hbase.procedure2.ProcedureExecutor.execProcedure(ProcedureExecutor.java:1650) ~[hbase-procedure-3.0.0-alpha-4-SNAPSHOT.jar:3.0.0-alpha-4-SNAPSHOT]
at org.apache.hadoop.hbase.procedure2.ProcedureExecutor.executeProcedure(ProcedureExecutor.java:1396) ~[hbase-procedure-3.0.0-alpha-4-SNAPSHOT.jar:3.0.0-alpha-4-SNAPSHOT]
at org.apache.hadoop.hbase.procedure2.ProcedureExecutor.access$1000(ProcedureExecutor.java:75) ~[hbase-procedure-3.0.0-alpha-4-SNAPSHOT.jar:3.0.0-alpha-4-SNAPSHOT]
at org.apache.hadoop.hbase.procedure2.ProcedureExecutor$WorkerThread.runProcedure(ProcedureExecutor.java:1962) ~[hbase-procedure-3.0.0-alpha-4-SNAPSHOT.jar:3.0.0-alpha-4-SNAPSHOT]
at org.apache.hadoop.hbase.trace.TraceUtil.trace(TraceUtil.java:216) ~[hbase-common-3.0.0-alpha-4-SNAPSHOT.jar:3.0.0-alpha-4-SNAPSHOT]
at org.apache.hadoop.hbase.procedure2.ProcedureExecutor$WorkerThread.run(ProcedureExecutor.java:1989) ~[hbase-procedure-3.0.0-alpha-4-SNAPSHOT.jar:3.0.0-alpha-4-SNAPSHOT]

We mock lots of things in this test so not sure this is a test issue or a real issue.

Need to dig more.

This should be a possible reason that why this test is flaky.