code: def get_evidences_by_pmid(graph: BELGraph, pmids: Union[str, Iterable[str]]):
      
      result = defaultdict(set)
  
      for _, _, _, data in filter_edges(graph, build_pmid_inclusion_filter(pmids)):
          result[data[CITATION][CITATION_REFERENCE]].add(data[EVIDENCE])
  
      return dict(result)
docs: Get a dictionary from the given PubMed identifiers to the sets of all evidence strings associated with each
      in the graph.
  
      :param graph: A BEL graph
      :param pmids: An iterable of PubMed identifiers, as strings. Is consumed and converted to a set.
      :return: A dictionary of {pmid: set of all evidence strings}
      :rtype: dict