public void setId(String id) {
            this.id = id;
        }
Sets an arbitrary, opaque ID which uniquely identifies this
connection. This ID may be used via the "join" (primaryConnection)
property of another connection to join (share) this connection while
it is in progress.

@param id
   An arbitrary, opaque, unique ID for this connection.
extensions/guacamole-auth-json/src/main/java/org/apache/guacamole/auth/json/user/UserData.java