the code below creates this diagram. I would like to to make all 3 subgraphs 5 nodes tall. so that, for example data_source_1, process_1 and product_1 are all horizontally aligned properly (same with process_5 and product_4). That would make the diagram better readable. is there a way of doing that? (I am using R to make the plot, but the issue is with the graphviz syntax).