@Override
    public void setAttributes(Map<String, String> attributes) {
        // Do nothing - there are no attributes
    }
Add a connection identifier to this connection group, and
return the identifier if the add succeeds, otherwise
return null.

@param identifier
    The identifier of the connection to add to the group.

@return
    The String identifier of the connection if the add
    operation was successful; otherwise null.
extensions/guacamole-auth-quickconnect/src/main/java/org/apache/guacamole/auth/quickconnect/QuickConnectionGroup.java