Why pylint keeps saying my class is R0923 - 'interface not implemented'

I am writing python classes with abc module to define abstract class and using sub-class to implement the abstract method. However, when i tried to use pylint to justify it, pylint keeps saying my subclass is "interface not implemented". I am a little bit confused how pylint regards a class is an interface. Could anyone shed some light on me?

Here is my example code. When i call pylint mytest.py, the result is as R0923: 17:MyClass: Interface not implemented.

import abc


class MyInterface(object):
    """docstring for MyInterface"""

    __metaclass__ = abc.ABCMeta

    def __init__(self, arg):
        self.arg = arg

    @abc.abstractmethod
    def test(self):
        pass


class MyClass(MyInterface):
    """docstring for MyClass"""
    def __init__(self, arg):
        super(MyClass, self).__init__(arg)

    def test(self):
        """docstring for test"""
        print self.arg