Represents the next interceptor in the chain.
As GroovyInterceptor, you intercept by doing one of the following:
Pass on to the next interceptor by calling one of the call() method,
possibly modifying the arguments and return values, intercepting an exception, etc.
Throws an exception to block the call.
Return some value without calling the next interceptor.
The signature of the call method is as follows:
The object whose method/property is accessed.
For constructor invocations and static calls, this is Class.
If the receiver is null, all the interceptors will be skipped.
The name of the method/property/attribute. Otherwise pass in null.
Arguments of the method call, index of the array access, and/or values to be set.
Multiple override of the call method is provided to avoid the implicit object
array creation, but otherwise they behave the same way.