def _eval_trace(self):
        trace = 0
        for i in range(self.cols):
            trace += self._mat[i*self.cols + i]
        return trace
Yield list of [[(name, image), ...], [(name, image), ...], ...]
dataset/ETHPy150Open sympy/sympy/sympy/matrices/dense.py/DenseMatrix._eval_trace--crossover with--dataset/ETHPy150Open realestate-com-au/harpoon/harpoon/layers.py/Layers.layered