code: public void setGroups(java.util.Collection<String> groups) {
          if (groups == null) {
              this.groups = null;
              return;
          }
  
          this.groups = new java.util.ArrayList<String>(groups);
      }
docs: The list of groups (20 maximum) to which the ActiveMQ user belongs. This value can contain only alphanumeric
  characters, dashes, periods, underscores, and tildes (- . _ ~). This value must be 2-100 characters long.
  
  @param groups
  The list of groups (20 maximum) to which the ActiveMQ user belongs. This value can contain only
  alphanumeric characters, dashes, periods, underscores, and tildes (- . _ ~). This value must be 2-100
  characters long.