What are the settings/rules used in instant reverse (code to UML Class diagrams)


I will like to know more about the settings of Visual Paradigm for converting source codes (Java, C++, .NET) into UML Class Diagrams. I am interested to know, for instance, how Visual Paradigm decide a segment of the coding should be translated into common association, generalization, composition, or even aggregation relationship - when converting source code into UML Class Diagram. I couldn’t find the relevant information from the user manual.