def _guess_type(self, full_path):
        return mimetypes.guess_type(full_path)[0] or 'text/plain'
fprop for deconv is equivalent to bprop for conv.
dataset/ETHPy150Open cloudera/hue/tools/ace-editor/static.py/Cling._guess_type--crossover with--dataset/ETHPy150Open NervanaSystems/neon/neon/layers/layer.py/Deconvolution.fprop