class_docstr: This class provides a set of methods to read, parse and answer
  questions about a single robots.txt file.
docstr: Returns the time the robots.txt file was last fetched.
  
  This is useful for long-running web spiders that need to
  check for new robots.txt files periodically.
docstr_tok: ["Returns","the","time","the","robots.txt","file","was","last","fetched",".","This","is","useful","for","long-running","web","spiders","that","need","to","check","for","new","robots.txt","files","periodically","."]
code: def mtime(self):
      """Returns the time the robots.txt file was last fetched.
  
      This is useful for long-running web spiders that need to
      check for new robots.txt files periodically.
  
      """
      return self.last_checked
  
imports: import collections
  import urllib.parse
  import urllib.request
label_desc: Use image node_id 2 for calling the RobotFileParser obj's underlying member method code with example usage: obj.mtime() and returns: self