code: public void addMatch(String name, PseudoClassType pseudoClass)
      {
          if (names == null)
              names = new HashMap<String, Set<PseudoClassType>>();
          
          Set<PseudoClassType> classes = names.get(name);
          if (classes == null)
          {
              classes = new HashSet<PseudoClassType>(2);
              names.put(name, classes);
          }
          classes.add(pseudoClass);
      }
docs: Assigns a pseudo class to the given element name. Element names are case-insensitive.
  Multiple pseudo classes may be assigned to a single element name.
  @param name the element name
  @param pseudoClass the pseudo class to be assigned