# Returns the `Bool` value corresponding the given key or `def_value` if none
	# or if the value isn't of correct type
	fun bool(key: String, def_value: Bool): Bool
	do
		sys.jni_env.push_local_frame(2)
		var return_value = shared_preferences.get_boolean(key.to_java_string, def_value)
		sys.jni_env.pop_local_frame
		return return_value
	end