code: def grep(source, regex, stop_on_first=False):
      
      loader = ClassLoader(source, max_cache=-1)
      r = re.compile(regex)
  
      def _matches(constant):
          return r.match(constant.value)
  
      for klass in loader.classes:
          it = loader.search_constant_pool(path=klass, type_=UTF8, f=_matches)
          if next(it, None):
              print(klass)
              if stop_on_first:
                  break
docs: Grep the constant pool of all classes in source.