@Test
public void testValidContentType() {

    // Arrange
    final DittoHeaders dittoHeaders = DittoHeaders.empty();
    final ContentType type = ContentTypes.APPLICATION_JSON;
    // Act
    final TestRouteResult result =
            testRoute(extractRequestContext(
                    ctx -> ensureValidContentType(Set.of(type.mediaType().toString()), ctx, dittoHeaders,
                            COMPLETE_OK)))
                    .run(HttpRequest.PUT("someUrl").withEntity(type, "something".getBytes()));
    // Assert
    result.assertStatusCode(StatusCodes.OK);
}