code: public int getMaxConnectionsPerUser() throws GuacamoleException {
  
          // Pull default from environment if per-user connection limit is unset
          Integer value = getModel().getMaxConnectionsPerUser();
          if (value == null)
              return environment.getDefaultMaxConnectionsPerUser();
  
          // Otherwise use defined value
          return value;
  
      }
docs: Returns the maximum number of connections that should be allowed to this
  connection for any individual user. If no limit applies, zero is
  returned.
  
  @return
  The maximum number of connections that should be allowed to this
  connection for any individual user, or zero if no limit applies.
  
  @throws GuacamoleException
  If an error occurs while parsing the concurrency limit properties
  specified within guacamole.properties.