np.where has not the same usage as numpy

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File "/usr/local/lib/python3.6/dist-packages/minpy/primitive.py", line 141, in call
return self.call(args, kwargs)
File "/usr/local/lib/python3.6/dist-packages/minpy/primitive.py", line 238, in call
result_value = self._func(*arg_values, **kwarg_values)
File "", line 62, in where
File "/usr/local/lib/python3.6/dist-packages/mxnet/_ctypes/ndarray.py", line 92, in _imperative_invoke
ctypes.byref(out_stypes)))
File "/usr/local/lib/python3.6/dist-packages/mxnet/base.py", line 251, in check_call
raise MXNetError(py_str(_LIB.MXGetLastError()))
mxnet.base.MXNetError: [07:52:08] src/c_api/../imperative/imperative_utils.h:336: Check failed: num_inputs == infered_num_inputs (1 vs. 3) Operator where expects 3 inputs, but got 1 instead.