>>> graph.concatenate(tensors=[x, x], axis=1, name="node_1")
<Tensor: name="node_1", operation_name="concatenate", shape=(2, 6)>
>>> result = qctrl.functions.calculate_graph(graph=graph, output_node_names=["node_1"])
>>> result.output["node_1"]["value"]
array([[1., 2., 3., 1., 2., 3.],
[4., 5., 6., 4., 5., 6.]])