public DocumentStoredFieldVisitor(String... fields){
  fieldsToAdd=new HashSet<>(fields.length);
  for (  String field : fields) {
    fieldsToAdd.add(field);
  }
}

public DocumentStoredFieldVisitor ( String ... fields ) { fieldsToAdd = new HashSet < > ( fields . length ) ; for ( String field : fields ) { fieldsToAdd . add ( field ) ; } }
load only fields named in the provided fields .
