@Test
  public void testDeallocateExceedPoolCapacity() throws Exception {
    final int capacity = 1024;
    SimpleByteBufferPool pool = new SimpleByteBufferPool(capacity);
    ByteBuffer singleBuffer = ByteBuffer.allocate(1);
    pool.deallocate(singleBuffer);
    assertEquals(capacity, pool.availableMemory());
  }
This scenario tests when a {@link SimpleByteBufferPool} deallocates a {@link ByteBuffer} that will make the
pool's total available memory to be larger than the pool's capacity. This operation should still suceed, and
set the pool's available memory the same as its capacity.
ambry-utils/src/test/java/com/github/ambry/utils/SimpleByteBufferPoolTest.java