@Test
public void extractPlaceholders_validURI_PlaceholdersInQueryStringOnly() {

	List<String> placeholders = URISignatureHandler
			.extractPlaceholders(validURI_PlaceholdersInQueryStringOnly);
	assertNotNull(placeholders);
	assertEquals(1, placeholders.size());
	assertEquals("Wrong first placeholder", "user_id", placeholders.get(0));
}