code: def _fix_slice(self, inputs, new_attr):
          
          begin = new_attr.get('begin')
          end = new_attr.get('end')
          axes = new_attr.get('axis', tuple(range(len(begin))))
          slice_op = mx.sym.slice_axis(inputs[0], axis=axes[0], begin=begin[0], end=end[0])
          if len(axes) > 1:
              for i, axis in enumerate(axes):
                  slice_op = mx.sym.slice_axis(slice_op, axis=axis, begin=begin[i], end=end[i])
          return slice_op
docs: onnx slice provides slicing on multiple axis. Adding multiple slice_axis operator
          for multiple axes from mxnet