static boolean test(Document doc) {
        return of(doc).isEnabled();
    }
Returns {@code true} if the specified {@link Document} should be 
considered {@code enabled}, else {@code false}.

@param doc  the document to test
@return     {@code true} if enabled, else {@code false}
runtime-parent/runtime-config/src/main/java/com/speedment/runtime/config/trait/HasEnabled.java