@Test
  public void testTooBigEntry() throws InterruptedException {
    Cacheable tooBigCacheable = Mockito.mock(Cacheable.class);
    Mockito.when(tooBigCacheable.getSerializedLength()).thenReturn(Integer.MAX_VALUE);
    this.bc.cacheBlock(this.plainKey, tooBigCacheable);
    doDrainOfOneEntry(this.bc, this.wt, this.q);
    assertTrue(bc.blocksByHFile.isEmpty());
    assertTrue(bc.getBackingMap().isEmpty());
  }
Pass through a too big entry and ensure it is cleared from queues and ramCache. Manually run
the WriterThread.
hbase-server/src/test/java/org/apache/hadoop/hbase/io/hfile/bucket/TestBucketWriterThread.java