code: private boolean isPluralAttribute(Field attribute)
      {
          return attribute.getType().equals(Collection.class) || attribute.getType().equals(Set.class)
                  || attribute.getType().equals(List.class) || attribute.getType().equals(Map.class);
      }
docs: Returns true, if attribute belongs plural hierarchy.
  
  @param attribute
  the attribute
  @return true, if attribute belongs plural hierarchy. else false.