@Override
  public Structure select(List<String> memberNames) {
    StructureDS result = new StructureDS(getParentGroup(), orgVar);
    List<Variable> members = new ArrayList<>();
    for (String name : memberNames) {
      Variable m = findVariable(name);
      if (null != m) members.add(m);
    }
    result.setMemberVariables(members);
    result.isSubset = true;
    return result;
  }
@ Override public Structure select ( List < String > memberNames ) { StructureDS result = new StructureDS ( getParentGroup ( ) , orgVar ) ; List < Variable > members = new ArrayList < > ( ) ; for ( String name : memberNames ) { Variable m = findVariable ( name ) ; if ( null != m ) members . add ( m ) ; } result . setMemberVariables ( members ) ; result . isSubset = true ; return result ; }
copy() doesnt work because convert gets called twice