- callback
- The method or lambda to be invoked for each element in the dictionary.
This method is used to iterate over all of the elements in the dictionary without having to know the names of the keys in the dictionary.
The callback is invoked with the name of the dictionary key and an boxed object. The type of the boxed object in the callback is one of: null value, boolean, int, float, string, CGPDFArray, CGPDFDictionary or CGPDFStream.