multiple added nodes in series

[jmccreight]

this error should not be necessary, but maybe a warning?

File E:\wrdapp\pywatershed\pywatershed\pywatershed\hydrology\prms_channel_flow_graph.py:885, in _build_flow_graph_inputs(prms_channel_dis, prms_channel_params, new_nodes_maker_dict, new_nodes_maker_names, new_nodes_maker_indices, new_nodes_flow_to_nhm_seg)    882 assert len(new_nodes_maker_names) == len(new_nodes_flow_to_nhm_seg), "NONO"    883 # I think this is the only condition to check with    884 # new_nodes_flow_to_nhm_seg--> 885 assert len(new_nodes_flow_to_nhm_seg) == len(    886     np.unique(new_nodes_flow_to_nhm_seg)    887 ), "OHNO"    889 nseg = prms_channel_params.dims["nsegment"]    890 nnodes = nseg + len(new_nodes_maker_names)