updatePixels method for Capture object

I am very new to processing and even more to Object Oriented Programming so probably the answer to the question is quite simple but is a conceptual one and I´d better ask.

I am doing some type of research about the video capabilities for computer vision of some processing libraries. I have started with the Core Library (processing.video.*) and after reading the description of the Capture object in the processing.org help here it seemed to me it was not quite powerful because it defines very few methods, to be more specific:

Nevertheless I came across some examples where another method is used: updatePixels() that provides much more options to play with but I am not able to find any information about it. I know it is used (and defined) as a method for the PImage but (and here comes the question) shouldn´t it be defined also under the Capture class?, perhaps I am missing a well documentation of the Capture class where it is defined but I didn´t find it in the web, is there any other methods for this class that I am missing? where can I find them?

Thanks in advance and brgds,