code: public void setUsers(java.util.Collection<User> users) {
          if (users == null) {
              this.users = null;
              return;
          }
  
          this.users = new java.util.ArrayList<User>(users);
      }
docs: Required. The list of ActiveMQ users (persons or applications) who can access queues and topics. This value can
  contain only alphanumeric characters, dashes, periods, underscores, and tildes (- . _ ~). This value must be
  2-100 characters long.
  
  @param users
  Required. The list of ActiveMQ users (persons or applications) who can access queues and topics. This
  value can contain only alphanumeric characters, dashes, periods, underscores, and tildes (- . _ ~). This
  value must be 2-100 characters long.