(PHP 5, PHP 7)
ReflectionClass::isUserDefined — Checks if user defined
public ReflectionClass::isUserDefined ( ) : bool
Checks whether the class is user-defined, as opposed to internal.
This function has no parameters.
 Returns true on success or false on failure. 
    © 1997–2020 The PHP Documentation Group
Licensed under the Creative Commons Attribution License v3.0 or later.
    https://www.php.net/manual/en/reflectionclass.isuserdefined.php