code: func (c *Comm) cleanUnusedConnections(serverCertsBeforeConfig StringSet) {
  	// Scan all nodes after the reconfiguration
  	serverCertsAfterConfig := c.serverCertsInUse()
  	// Filter out the certificates that remained after the reconfiguration
  	serverCertsBeforeConfig.subtract(serverCertsAfterConfig)
  	// Close the connections to all these nodes as they shouldn't be in use now
  	for serverCertificate := range serverCertsBeforeConfig {
  		c.Connections.Disconnect([]byte(serverCertificate))
  	}
  }
docs: // cleanUnusedConnections disconnects all connections that are un-used
  // at the moment of the invocation