code: def resolve_config_file_path(self, config_filepath):
          
          search_paths = [config_filepath,
                          os.path.normpath(os.path.join(os.getcwd(), config_filepath)),
                          os.path.normpath(os.path.join(os.path.dirname(os.path.abspath(__file__)), config_filepath))]
  
          for search_path in search_paths:
              try:
                  self.validate_config_file(search_path)
                  return search_path
              except (IOError, OSError):
                  pass
  
          raise errors.SourceError(
              'No config file found in current working directory or nomenclate/core and %s is not a valid YAML file')
docs: Determines whether given path is valid, and if so uses it.
              Otherwise searches both the working directory and nomenclate/core for the specified config file.
  
          :param config_filepath: str, file path or relative file name within package
          :return: str, resolved full file path to the config file