code: func (c *ConnectionStore) Connection(endpoint string, expectedServerCert []byte) (*grpc.ClientConn, error) {
  	c.lock.RLock()
  	conn, alreadyConnected := c.Connections.Lookup(expectedServerCert)
  	c.lock.RUnlock()
  
  	if alreadyConnected {
  		return conn, nil
  	}
  
  	// Else, we need to connect to the remote endpoint
  	return c.connect(endpoint, expectedServerCert)
  }
docs: // Connection obtains a connection to the given endpoint and expects the given server certificate
  // to be presented by the remote node