class_docstr: This class provides a set of methods to read, parse and answer
  questions about a single robots.txt file.
code: def _add_entry(self, entry):
      if "*" in entry.useragents:
          # the default entry is considered last
          if self.default_entry is None:
              # the first default entry wins
              self.default_entry = entry
      else:
          self.entries.append(entry)
  
imports: import collections
  import urllib.parse
  import urllib.request
label_desc: Use image node_id 6 for calling the RobotFileParser obj's underlying member method code with example usage: obj._add_entry(entry) without return types