@Test
public void testWithUpperCaseContentTypeHeaderName() {

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