parameters: (self, string)
docstring: Add a string to the command.
docstring_summary: Add a string to the command.
docstring_tokens: Add a string to the command .
function: def add(self, string):
          """Add a string to the command."""
          self._command = "{}{}{}".format(self._command, self._space(), string)
function_tokens: def add ( self , string ) : self . _command = "{}{}{}" . format ( self . _command , self . _space ( ) , string )