code: def check(self, radl):
          
  
          SIMPLE_FEATURES = {
              "host": (str, None),
              "credentials.username": (str, None),
              "credentials.password": (str, None),
              "credentials.private_key": (str, None)
          }
          self.check_simple(SIMPLE_FEATURES, radl)
  
          if not self.getHost():
              raise RADLParseException("Ansible host must have a host", line=self.line)
          (username, password, private_key) = self.getCredentialValues()
          if not username:
              raise RADLParseException("Ansible host must have a credentials.username", line=self.line)
          if not password and not private_key:
              raise RADLParseException("Ansible host must have a credentials.password or credentials.private_key",
                                       line=self.line)
docs: Check the features in this network.