'sum of elements matrix[(row1,col1)..(row2,col2)], inclusive.
:type row1: int
:type col1: int
:type row2: int
:type col2: int
:rtype: int'

def sumRegion(self, row1, col1, row2, col2):

    return (((self.__sums[(row2 + 1)][(col2 + 1)] - self.__sums[(row2 + 1)][col1]) - self.__sums[row1][(col2 + 1)]) + self.__sums[row1][col1])
