Delegation design pattern with abstract methods in python

I have the following classes implementing a "Delegation Design Pattern" with an additional DelegatorParent class:

class DelegatorParent():

    def __init__(self):
        self.a = 'whatever'    

class ConcreteDelegatee():

    def myMethod(self):
        return 'myMethod'


class Delegator(DelegatorParent):

    def __init__(self):
        self.delegatee = ConcreteDelegatee()
        DelegatorParent.__init__(self)

    def __getattr__(self, attrname):
        return getattr(self.delegatee, attrname)

a = Delegator()
result = a.myMethod()

Everything looks fine.

Now I would like to put an abstract method in DelegatorParent, to ensure that "myMethod" is always defined.

from abc import ABCMeta, abstractmethod

class DelegatorParent():
    __metaclass__ = ABCMeta

    @abstractmethod
    def myMethod(self):
        pass

    def __init__(self):
        self.a = 'whatever'


class ConcreteDelegatee():

    def myMethod(self):
        return 'myMethod'


class Delegator(DelegatorParent):

    def __init__(self):
        self.delegatee = ConcreteDelegatee()
        DelegatorParent.__init__(self)

    def __getattr__(self, attrname):
        return getattr(self.delegatee, attrname)

    # This method seems unnecessary, but if I erase it an exception is
    # raised because the abstract method's restriction is violated
    def myMethod(self): 
        return self.delegatee.myMethod()


a = Delegator()
result = a.myMethod()

Can you help me find an "elegant" way to remove "myMethod" from "Delegator"... Intuition tells me that it is somehow redundant (considering that a custom getattr method is defined).

And more importantly, notice that with this implementation, if I forget to define myMethod in ConcreteDelegatee the program compiles, but it may crash in runtime if I call Delegator.myMethod(), which is exactly what I wanted to avoid by using abstract methods in DelegatorParent.

Obviously a simple solution would be to move @abstractmethod to the Delegator class, but I want to avoid doing that because in my program DelegatorParent is a very important class (and Delegator is just an auxiliary class).