public void setGroups(List<String> groups) {
      if (this.groups == null) {
        this.groups = new ArrayList<>();
      }
      if (this.groups == groups) {
        return;
      }
      this.groups.clear();
      if (groups != null) {
        this.groups.addAll(groups);
      }
    }
@param groups the groups to set
ql/src/java/org/apache/hadoop/hive/ql/exec/repl/ranger/RangerPolicy.java