code: func ReadClientText(rw io.ReadWriter) ([]byte, error) {
  	p, _, err := readData(rw, ws.StateServerSide, ws.OpText)
  	return p, err
  }
docs: // ReadClientText reads next text message from rw, considering that caller
  // represents server side. It is a shortcut for ReadData(rw, ws.StateServerSide).
  // It discards received binary messages.
  //
  // Note this may handle and write control frames into the writer part of a
  // given io.ReadWriter.