public function visitNullType(NullType $type)
    {
        $this->typeCheck->visitNullType(func_get_args());

        return new StrictEquals(
            $this->valueExpression(),
            new Literal(null)
        );
    }
public function visitNullType(NullType $type)
    {
        $this->typeCheck->visitNullType(func_get_args());

        return new StrictEquals(
            $this->valueExpression(),
            new Literal(null)
        );
    }
@param NullType $type

@return StrictEquals