presto-main/src/main/java/io/prestosql/execution/buffer/LazyOutputBuffer.java/LazyOutputBuffer/getInfo
class LazyOutputBuffer:    @Override
    public OutputBufferInfo getInfo()
    {
        OutputBuffer outputBuffer;
        synchronized (this) {
            outputBuffer = delegate;
        }

        if (outputBuffer == null) {
            //
            // NOTE: this code must be lock free to not hanging state machine updates
            //
            BufferState state = this.state.get();

            return new OutputBufferInfo(
                    "UNINITIALIZED",
                    state,
                    state.canAddBuffers(),
                    state.canAddPages(),
                    0,
                    0,
                    0,
                    0,
                    ImmutableList.of());
        }
        return outputBuffer.getInfo();
    }