docs: def transcript_sort_key(transcript):
      """
      Key function used to sort transcripts. Taking the negative of
      protein sequence length and nucleotide sequence length so that
      the transcripts with longest sequences come first in the list. This couldn't
      be accomplished with `reverse=True` since we're also sorting by
      transcript name (which places TP53-001 before TP53-002).
      """
      return (
          -len(transcript.protein_sequence),
          -len(transcript.sequence),
          transcript.name
      )