### Question:
Request extends Message<Request> { public Map<String, Collection<String>> parameters() { return unmodifiableMap(parameters); }  @Override String item(); @Override Request request(); Future<Response> reply(final int status); Future<Response> reply(final Function<Response, Response> mapper); boolean safe(); boolean collection(); boolean role(final Object... roles); boolean role(final Collection<Object> roles); Optional<Object> user(); Request user(final Object user); Set<Object> roles(); Request roles(final Object... roles); Request roles(final Collection<Object> roles); String method(); Request method(final String method); String base(); Request base(final String base); String path(); Request path(final String path); String query(); Result<Query, Failure> query(final Format<?> format, final Shape shape); Request query(final String query); Map<String, Collection<String>> parameters(); Request parameters(final Map<String, ? extends Collection<String>> parameters); Optional<String> parameter(final String name); Request parameter(final String name, final String value); List<String> parameters(final String name); Request parameters(final String name, final String... values); Request parameters(final String name, final Collection<String> values); static final String GET; static final String HEAD; static final String POST; static final String PUT; static final String PATCH; static final String DELETE; static final String CONNECT; static final String OPTIONS; static final String TRACE; }### Answer:
@Test void testParametersIgnoreEmptyHeaders() { final Request request=new Request() .parameters("parameter", emptySet()); assertThat(request.parameters().entrySet()).isEmpty(); }