public function updateInstruction($index, $function, $argument)
    {
        if (!empty($argument) && ctype_print($argument)) {
            $this->instructions[$index]->$function($argument);
        }

        return $this;
    }
public function updateInstruction($index, $function, $argument)
    {
        if (!empty($argument) && ctype_print($argument)) {
            $this->instructions[$index]->$function($argument);
        }

        return $this;
    }
public function updateInstruction ( $ index , $ function , $ argument ) { if ( ! empty ( $ argument ) && ctype_print ( $ argument ) ) { $ this -> instructions [ $ index ] -> $ function ( $ argument ) ; } return $ this ; }
Update Instruction - Supply an index of the instruction to update,
plus the function and single argument, to do something to an instruction.

@param $index
@param $function
@param $argument
@return $this
Update Instruction - Supply an index of the instruction to update plus the function and single argument to do something to an instruction .