public function appendArg($arg)
    {
        Assertion::string($arg);
        $this->args = $this->args->append($arg);
    }
public function appendArg($arg)
    {
        Assertion::string($arg);
        $this->args = $this->args->append($arg);
    }
public function appendArg ( $ arg ) { Assertion :: string ( $ arg ) ; $ this -> args = $ this -> args -> append ( $ arg ) ; }
Append an argument to the list of arguments to be passed to the program.

@param string $arg
Append an argument to the list of arguments to be passed to the program .