Bidirectional linking of entities currently fails due to recursion error

I basically tried the following:

                                Block:
                                  # Experiment: $Experiment
                                  block_number: $block_number
                                  CombinedFile: $CombinedFileObject
                                Experiment:
                                  blocks: +$Block

and received a:

(...)
    self.create_flat_list([p.value], flat)
  File "/home/salexan/Projekte/CaosDB/caosdb-newcrawler/src/newcrawler/crawl.py", line 451, in create_flat_list
    self.create_flat_list([el], flat)
  File "/home/salexan/Projekte/CaosDB/caosdb-newcrawler/src/newcrawler/crawl.py", line 456, in create_flat_list
    self.create_flat_list([p.value], flat)
  File "/home/salexan/Projekte/CaosDB/caosdb-newcrawler/src/newcrawler/crawl.py", line 445, in create_flat_list
    if isinstance(p.value, list):
RecursionError: maximum recursion depth exceeded

• confirm with regression test (don't fix unless that fits into the (B )
• move issue to next iteration and reevaluate weight