code: def utterances_from_eaf(eaf_path: Path, tier_prefixes: Tuple[str, ...]) -> List[Utterance]:
      
  
      if not eaf_path.is_file():
          raise FileNotFoundError("Cannot find {}".format(eaf_path))
  
      eaf = Eaf(eaf_path)
      utterances = []
      for tier_name in sorted(list(eaf.tiers)): # Sorting for determinism
          for tier_prefix in tier_prefixes:
              if tier_name.startswith(tier_prefix):
                  utterances.extend(utterances_from_tier(eaf, tier_name))
                  break
      return utterances
docs: Extracts utterances in tiers that start with tier_prefixes found in the ELAN .eaf XML file
      at eaf_path.
  
      For example, if xv@Mark is a tier in the eaf file, and
      tier_prefixes = ["xv"], then utterances from that tier will be gathered.