@Before
  public void setup() {
    coord = mock(ProcedureCoordinator.class);
    final ProcedureCoordinatorRpcs comms = mock(ProcedureCoordinatorRpcs.class);
    when(coord.getRpcs()).thenReturn(comms); // make it not null
  }
Demonstrate how Procedure handles single members, multiple members, and errors semantics
hbase-server/src/test/java/org/apache/hadoop/hbase/procedure/TestProcedure.java