Assert first node is a TensorType.

theano/sandbox/rng_mrg.py

@@ -475,7 +475,7 @@ class mrg_uniform(mrg_uniform_base):
         # If we try to use the C code here with something else than a
         # TensorType, something is wrong (likely one of the GPU ops
         # not defining C code correctly).
-        # NB: first node should always be a TensorType, as it is created with as_tensor_variable() into make_node.
+        assert isinstance(node.inputs[0].type, TensorType)
         return """
         //////// <code generated by mrg_uniform>
         npy_int64 odims_i;