public Structure select( String varName) {
    List<String> memberNames = new ArrayList<>(1);
    memberNames.add(varName);
    return  select(memberNames);
  }
public Structure select( String varName) {
    List<String> memberNames = new ArrayList<>(1);
    memberNames.add(varName);
    return  select(memberNames);
  }
public Structure select ( String varName ) { List < String > memberNames = new ArrayList <> ( 1 ) ; memberNames . add ( varName ) ; return select ( memberNames ) ; }
Create a subset of the Structure consisting only of the one member variable
@param varName name of member Variable
@return containing just that member
Create a subset of the Structure consisting only of the one member variable