code: def example_bigbeds():
      
      hits = []
      d = data_dir()
      for fn in os.listdir(d):
          fn = os.path.join(d, fn)
          if os.path.splitext(fn)[-1] == '.bigBed':
              hits.append(os.path.abspath(fn))
      return hits
docs: Returns list of example bigBed files