def METHOD_NAME(self, node):
    value = self.construct_scalar(node)
    b_ciphertext_data = to_bytes(value)
    # could pass in a key id here to choose the vault to associate with
    # TODO/FIXME: plugin vault selector
    vault = self._vaults['default']
    if vault.secrets is None:
        raise ConstructorError(context=None, context_mark=None,
                               problem="found !vault but no vault password provided",
                               problem_mark=node.start_mark,
                               note=None)
    ret = AnsibleVaultEncryptedUnicode(b_ciphertext_data)
    ret.vault = vault
    ret.ansible_pos = self._node_position_info(node)
    return ret