Reference: can

can

$sub = $obj->can(method)

Checks if object $obj has a method method. If so, returns a reference to the subroutine, otherwise returns undef. Can be called as either a static or object method call, or as a subroutine:

$ref = UNIVERSAL::can(val, method)

Returns a reference to the subroutine if val is a blessed reference with a method method, and undef if val is not blessed or does not have method.