@Override
  public void copy(int offset, MemoryChunk other, int otherOffset, int count) {
    FakeAshmemMemoryChunk that = (FakeAshmemMemoryChunk) other;
    // NULLSAFE_FIXME[Nullable Dereference]
    int numToCopy = Math.min(count, mBuf.length - offset);
    // NULLSAFE_FIXME[Parameter Not Nullable]
    System.arraycopy(mBuf, offset, that.mBuf, otherOffset, numToCopy);
  }
A fake implementation of {@link com.facebook.memory.ashmem.AshmemMemoryChunk} to allow us to test
out pools and other functionality. This uses byte arrays instead of actual ashmem memory, but
supports the same public interface
memory-types/ashmem/src/test/java/com/facebook/imagepipeline/testing/FakeAshmemMemoryChunk.java