Using has_type(list(Type), X) with user created type not working as expected

Help!
1

When using has_type/2 added more types via multifile which are working fine.

Then wanted to use

has_type(list(Type), X) :-
    is_list(X), element_types(X, Type).

by calling has_type/2 from the module importing the library errors, and the code started failing.

As near as I can figure, element_types/2 (GitHub) needs to be exported.

Example 

:- module(example, []).

:- use_module(library(error)).

% :- use_module(library(error),
%     [
%         element_types/2
%     ]).

:- multifile
    error:has_type/2.

error:has_type(key_value,Key_value) :-
    key_value_validate(Key_value).

key_value_validate(Key_value) :-
    must_be(ground,Key_value),
    Key_value = kv(Key,Value),
    must_be(ground,Key),
    must_be(ground,Value).

:- begin_tests(example_bad).

test(1) :-
    has_type(list(key_value),[kv(1,a),kv(2,b)]).

:- end_tests(example_bad).

has_type_workaround(list(Type), X) :-
    is_list(X), error:element_types(X, Type).

:- begin_tests(example_workaround).

test(2) :-
    has_type_workaround(list(key_value),[kv(1,a),kv(2,b)]).

:- end_tests(example_workaround).

?- run_tests.
% PL-Unit: example_bad 
ERROR: d:/has_type_list_example.pl:28:
        test 1: received error: plunit_example_bad:'unit body'/2: Unknown procedure: plunit_example_bad:has_type/2
 done
% PL-Unit: example_workaround . done
% 1 test failed
% 1 tests passed
false.

Also tried using

:- use_module(library(error),
    [
        element_types/2
    ]).

instead of

:- use_module(library(error)).

which resulted in

?- consult('D:/has_type_list_example.pl').
Warning: d:/has_type_list_example.pl:9:
Warning:    import/1: error:element_types/2 is not exported (still imported into example)
true.

Can use_module/2 be used to import predicates from modules that did not export the predicate? This has me confused.