code: def get_atlas_zonefile_data( zonefile_hash, zonefile_dir, check=True ):
      
      zonefile_path = atlas_zonefile_path(zonefile_dir, zonefile_hash)
      zonefile_path_legacy = atlas_zonefile_path_legacy(zonefile_dir, zonefile_hash)
  
      for zfp in [zonefile_path, zonefile_path_legacy]:
  
          if not os.path.exists( zfp ):
              continue
  
          if check:
              res = _read_atlas_zonefile(zfp, zonefile_hash)
          else:
              res = _read_atlas_zonefile(zfp, None)
  
          if res:
              return res
  
      return None
docs: Get a serialized cached zonefile from local disk 
      Return None if not found