Calls a user defined function or method given by the callback parameter, with the following arguments. This function must be called within a method context, it can't be used outside a class. It uses the late static binding.
The function or method to be called. This parameter may be an array, with the name of the class, and the method, or a string, with a function name.
Zero or more parameters to be passed to the function.
Returns the function result, or false on error.