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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _calc_priority_filter(row, pops):
 """Calculate the priority filter based on external associated data. - Pass high/medium impact variants not found in population databases - Pass variants found in COSMIC or Clinvar provided they don't have two additional reasons to filter (found in multiple external populations) """

    filters = []
    passes = []
    passes.extend(_find_known(row))
    filters.extend(_known_populations(row, pops))
    if len(filters) == 0 or (len(passes) > 0 and len(filters) < 2):
        passes.insert(0, "pass")
    return ",".join(passes + filters)