SizeMessage extends PartitionMessage { @Override protected boolean failIfRegionMissing() { return false; } SizeMessage(); private  SizeMessage(Set recipients, int regionId, ReplyProcessor21 processor,
      ArrayList<Integer> bucketIds, boolean estimate); static SizeResponse send(Set recipients, PartitionedRegion r, ArrayList<Integer> bucketIds,
      boolean estimate); @Override boolean isSevereAlertCompatible(); @Override int getDSFID(); @Override void fromData(DataInput in,
      DeserializationContext context); @Override void toData(DataOutput out,
      SerializationContext context); static final short ESTIMATE; }
@Test public void shouldBeMockable() throws Exception { SizeMessage mockSizeMessage = mock(SizeMessage.class); when(mockSizeMessage.failIfRegionMissing()).thenReturn(true); assertThat(mockSizeMessage.failIfRegionMissing()).isTrue(); }