code: public boolean containsTagHandler(String ns, String localName)
      {
          for (int i = 0; i < this.libraries.length; i++)
          {
              if (this.libraries[i].containsTagHandler(ns, localName))
              {
                  return true;
              }
          }
          return false;
      }
docs: /*
  (non-Javadoc)
  
  @see org.apache.myfaces.view.facelets.tag.TagLibrary#containsTagHandler(java.lang.String, java.lang.String)