mermaid confused when reusing collections #167
Description
If you have a pipeline with 2 Decimate collections then each has a unit named DOWNSAMPLE.
Mermaid will only draw one DOWNSAMPLE box in the first collection and not in the second. The unit will have 2x INPUT_SIGNAL and 2x OUTPUT_SIGNAL boxes, with one of the pairs pointing to its correct counterparts in the second collection.
This is not a problem with graphviz.
I noticed this issue before the recent PR that alters the graphing code.