code: def unset_config_value(self, name, quiet=False):
          
  
          config_data = self._read_config_file()
  
          if name in config_data:
  
              del config_data[name]
  
              self._write_config_file(config_data)
  
              if not quiet:
                  self.print_config_value(name, separator=' is now set to: ')
docs: unset a configuration value
              Parameters
             ==========
             name: the name of the value to unset (remove key in dictionary)
             quiet: disable verbose output if True (default is False)