private static boolean isValid(final String path) {
        return !isInvalidPath(path);
    }
Create a new ClassPathResource for ClassLoader usage.
A leading slash will be removed, as the ClassLoader
resource access methods will not accept it.

@param path        the absolute path within the classpath
@param classLoader the class loader to load the resource with,
                   or {@code null} for the thread context class loader
@see ClassLoader#getResourceAsStream(String)
src/main/java/spark/resource/ClassPathResource.java