You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: accumulateSquare.m
    path of file: ./repos/mexopencv/+cv
    
    the code of the file until where you have to start completion: %ACCUMULATESQUARE  Adds the square of a source image to the accumulator image
%
%     dst = cv.accumulateSquare(sr
    
function adds the input image `src` or its selected region, raised to a
% power of 2, to the accumulator `dst`:
%
%     dst(x,y) = dst(x,y) + src(x,y)^2  if mask(x,y)~=0
%
% The function supports multi-channel images. Each channel is processed
% independ