Returns true if the given object can be considered to be an instance of the class cls. This is done by testing the prototype chain of the object and checking at each level to see if the prototype is an instance of the given class.
object
cls
Object to test
Class to test for.
Returns true if the given
objectcan be considered to be an instance of the classcls. This is done by testing the prototype chain of the object and checking at each level to see if the prototype is an instance of the given class.