private static String formatMessage(Class<?> extensionClass, String formatString) {
        return format(formatString, extensionClass == null ? "<null>" : extensionClass.getSimpleName());
    }
Creates an instance with an extension type and a custom message.

@param message The message format for the exception. Must contain exactly one <code>%s</code> placeholder for the extension class name.
@param extensionClass The extension type. Can be null.
@param cause A throwable that caused this exception.
core/src/main/java/org/jdbi/v3/core/extension/NoSuchExtensionException.java