new_contents: from bioframe.region import parse_region
  import pytest
  
  
  def test_parse_region():
      # UCSC-style names
      assert parse_region("chr21") == ("chr21", 0, None)
      assert parse_region("chr21:1000-2000") == ("chr21", 1000, 2000)
      assert parse_region("chr21:1,000-2,000") == ("chr21", 1000, 2000)
  
      # Ensembl style names
      assert parse_region("6") == ("6", 0, None)
      assert parse_region("6:1000-2000") == ("6", 1000, 2000)
      assert parse_region("6:1,000-2,000") == ("6", 1000, 2000)
  
      # FASTA style names
      assert parse_region("gb|accession|locus") == ("gb|accession|locus", 0, None,)
      assert parse_region("gb|accession|locus:1000-2000") == (
          "gb|accession|locus",
          1000,
          2000,
      )
      assert parse_region("gb|accession|locus:1,000-2,000") == (
          "gb|accession|locus",
          1000,
          2000,
      )
  
      # Punctuation in names (aside from :)
      assert parse_region("name-with-hyphens-") == ("name-with-hyphens-", 0, None,)
      assert parse_region("GL000207.1") == ("GL000207.1", 0, None)
      assert parse_region("GL000207.1:1000-2000") == ("GL000207.1", 1000, 2000)
  
      # Trailing dash
      assert parse_region("chr21:1000-") == ("chr21", 1000, None)
  
      # Humanized units
      assert parse_region("6:1kb-2kb") == ("6", 1000, 2000)
      assert parse_region("6:1k-2000") == ("6", 1000, 2000)
      assert parse_region("6:1kb-2M") == ("6", 1000, 2000000)
      assert parse_region("6:1Gb-") == ("6", 1000000000, None)
  
      with pytest.raises(ValueError):
          parse_region("chr1:2,000-1,000")  # reverse selection
          parse_region("chr1::1000-2000")  # more than one colon
  
subject: Add tests to make CI happy