docs: def DeleteSignedBinary(binary_urn,
                         token = None):
    """Deletes the binary with the given urn from the datastore.
  
    Args:
      binary_urn: RDFURN that serves as a unique identifier for the binary.
      token: ACL token to use with the legacy (non-relational) datastore.
  
    Raises:
      SignedBinaryNotFoundError: If the signed binary does not exist.
    """
    if _ShouldUseLegacyDatastore():
      try:
        aff4.FACTORY.Open(
            binary_urn, aff4_type=aff4.AFF4Stream, mode="r", token=token)
      except aff4.InstantiationError:
        raise SignedBinaryNotFoundError(binary_urn)
      aff4.FACTORY.Delete(binary_urn, token=token)
  
    if data_store.RelationalDBEnabled():
      try:
        data_store.REL_DB.ReadSignedBinaryReferences(
            _SignedBinaryIDFromURN(binary_urn))
      except db.UnknownSignedBinaryError:
        if _ShouldUseLegacyDatastore():
          # Migration of data isn't complete yet (we haven't started reading
          # exclusively from the relational DB), so this is probably ok.
          return
        else:
          raise SignedBinaryNotFoundError(binary_urn)
      data_store.REL_DB.DeleteSignedBinaryReferences(
          _SignedBinaryIDFromURN(binary_urn))