code: def lower_camel(string, prefix='', suffix=''):
      
  
      return require_valid(append_underscore_if_keyword(''.join(
          word.lower() if index == 0 else upper_case_first_char(word)
          for index, word in enumerate(en.words(' '.join([prefix, string, suffix]))))
      ))
docs: Generate a camel-case identifier.
      Useful for unit test methods.
  
      Takes a string, prefix, and optional suffix.
  
      `prefix` can be set to `''`, though be careful - without a prefix, the
      function will throw `InvalidIdentifier` when your string starts with a
      number.
  
      Example:
          >>> lower_camel("User can login", prefix='test')
          'testUserCanLogin'