docs: @Override
      public boolean contains(IEntityGroup group, IGroupMember member) throws GroupsException {
  
          String groupContainerName = group.getLocalKey();
          String groupMemberName = member.getKey();
  
          if (!validKey(groupContainerName) || !validKey(groupMemberName)) {
              return false;
          }
  
          GcHasMember gcHasMember = new GcHasMember();
          gcHasMember.assignGroupName(groupContainerName);
          gcHasMember.addSubjectLookup(new WsSubjectLookup(null, "g:gsa", groupMemberName));
          WsHasMemberResults wsHasMemberResults = gcHasMember.execute();
          if (GrouperClientUtils.length(wsHasMemberResults.getResults()) == 1) {
              WsHasMemberResult wsHasMemberResult = wsHasMemberResults.getResults()[0];
              return StringUtils.equals(
                      "IS_MEMBER", wsHasMemberResult.getResultMetadata().getResultCode());
          }
          return false;
      }