code: public void setBuffer (Buffer buffer)
      {
          _queue.clear();
          if (buffer != null) {
              _queue.add(buffer);
          }
          AL10.alSourcei(_id, AL10.AL_BUFFER, buffer == null ? AL10.AL_NONE : buffer.getId());
      }
docs: Sets the source buffer.  Equivalent to unqueueing all buffers, then queuing the provided
  buffer.  Cannot be called when the source is playing or paused.
  
  @param buffer the buffer to set, or <code>null</code> to clear.