code: func (c *rawConnection) Start() {
  	c.startGoroutine(c.readerLoop)
  	c.startGoroutine(c.writerLoop)
  	c.startGoroutine(c.pingSender)
  	c.startGoroutine(c.pingReceiver)
  }
docs: // Start creates the goroutines for sending and receiving of messages. It must
  // be called exactly once after creating a connection.