public void setMaxConnectionsPerUser(Integer maxConnectionsPerUser) {
        this.maxConnectionsPerUser = maxConnectionsPerUser;
    }
Sets the maximum number of connections that can be established to this
connection concurrently by any one user.

@param maxConnectionsPerUser
    The maximum number of connections that can be established to this
    connection concurrently by any one user, zero if no restriction
    applies, or null if the default restrictions should be applied.
extensions/guacamole-auth-jdbc/modules/guacamole-auth-jdbc-base/src/main/java/org/apache/guacamole/auth/jdbc/connection/ConnectionModel.java