class Base(object):

    '''

    >>> base = Base()

    >>> print(base.noargs())

    Base

    >>> print(base.int_arg(1))

    Base

    >>> print(base._class())

    Base

    '''

    def noargs(self):

        return "Base"

    def int_arg(self, i):

        return "Base"

    @classmethod

    def _class(tp):

        return "Base"

class Derived(Base):

    '''

    >>> derived = Derived()

    >>> print(derived.noargs())

    Derived

    >>> print(derived.int_arg(1))

    Derived

    >>> print(derived._class())

    Derived

    '''

    def noargs(self):

        return "Derived"

    def int_arg(self, i):

        return "Derived"

    @classmethod

    def _class(tp):

        return "Derived"

class DerivedDerived(Derived):

    '''

    >>> derived = DerivedDerived()

    >>> print(derived.noargs())

    DerivedDerived

    >>> print(derived.int_arg(1))

    DerivedDerived

    >>> print(derived._class())

    DerivedDerived

    '''

    def noargs(self):

        return "DerivedDerived"

    def int_arg(self, i):

        return "DerivedDerived"

    @classmethod

    def _class(tp):

        return "DerivedDerived"

class Derived2(Base):

    '''

    >>> derived = Derived2()

    >>> print(derived.noargs())

    Derived2

    >>> print(derived.int_arg(1))

    Derived2

    >>> print(derived._class())

    Derived2

    '''

    def noargs(self):

        return "Derived2"

    def int_arg(self, i):

        return "Derived2"

    @classmethod

    def _class(tp):

        return "Derived2"