def METHOD_NAME(
    hpke_kem: hpke_pb2.HpkeKem, hpke_kdf: hpke_pb2.HpkeKdf,
    hpke_aead: hpke_pb2.HpkeAead,
    output_prefix_type: tink_pb2.OutputPrefixType) -> tink_pb2.KeyTemplate:
  """Creates an HPKE KeyTemplate, and fills in its values."""
  key_format = hpke_pb2.HpkeKeyFormat()
  key_format.params.kem = hpke_kem
  key_format.params.kdf = hpke_kdf
  key_format.params.aead = hpke_aead
  key_template = tink_pb2.KeyTemplate(
      type_url='type.googleapis.com/google.crypto.tink.HpkePrivateKey',
      value=key_format.SerializeToString(),
      output_prefix_type=output_prefix_type,
  )
  return key_template