// Set the deferred field directly since it's a public field
        mockNdrBuffer.deferred = mockDeferredNdrBuffer;
        // Set up deferred buffer chain to avoid NPE
        mockDeferredNdrBuffer.deferred = mockDeferredNdrBuffer; // Self-reference to avoid NPE
        lenient().when(mockNdrBuffer.derive(anyInt())).thenReturn(mockDeferredNdrBuffer);
        lenient().when(mockDeferredNdrBuffer.derive(anyInt())).thenReturn(mockDeferredNdrBuffer);

    public boolean hasNext() {
      while (!checkNotNull(iterator).hasNext()) {
        // this weird checkNotNull positioning appears required by our tests, which expect
        // both hasNext and next to throw NPE if an input iterator is null.

        topMetaIterator = getTopMetaIterator();
        if (topMetaIterator == null) {
          return false;
        }

        iterator = topMetaIterator.next();