class_docstr: This class provides a set of methods to read, parse and answer
  questions about a single robots.txt file.
code: def __str__(self):
      entries = self.entries
      if self.default_entry is not None:
          entries = entries + [self.default_entry]
      return "\n\n".join(map(str, entries))
  
imports: import collections
  import urllib.parse
  import urllib.request
label_desc: Use image node_id 12 for calling the RobotFileParser obj's underlying member method code with example usage: obj.__str__() and returns: str