code: def execute_file(self, filename):
          
          logger.info("Executing file: %s", format_path(filename))
          contents = self.context.execute(filename, capture=True).stdout
          num_lines = len(contents.splitlines())
          logger.debug("Execution of %s yielded % of output.",
                       format_path(filename),
                       pluralize(num_lines, 'line'))
          return contents.rstrip()
docs: Execute a file and provide feedback to the user.
  
          :param filename: The pathname of the file to execute (a string).
          :returns: Whatever the executed file returns on stdout (a string).