code: public DataSlice getAssembledContent() {
      if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled()) JmfTr.entry(this, tc, "getAssembledContent");
  
      DataSlice result = null;
  
      // We can only return something useful if the encoding is a JMFMessage.
      if (encoding instanceof JMFMessage) {
  
        // So we just ask the encoding to return what it has (or null)
        result = ((JMFMessage)encoding).getAssembledContent();
      }
  
      if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled()) JmfTr.exit(this, tc, "getAssembledContent", result);
      return result;
    }
docs: /*
  Return a DataSlice containing the assembled message content, or null if the
  message is not assembled.
  See JMFMessage for javadoc description.
  d348294
  Locking: No necessaity to lock - encoding won't suddenly become something other
  than a JMFMessage, and the encoding.getAssembledContent() method will
  take the lock before doing the real work.