#You can use mypy to perform a static typecheck
#For more details on typing see
#https://docs.python.org/3/library/typing.html
from typing import List

class MyAlmostInterface:
    def do_stuffA(self, x: str, y: int) -> str:
        pass
    def do_stuffB(self, x:int) -> List[int]:
        pass
        
class InterfaceImpl(MyAlmostInterface):
    def do_stuffA(self, x: str, y: int) -> str:
        return x
    def do_stuffB(self, x:int) -> List[int]:
        return [x+1, x]
        
        
def fun(ii: MyAlmostInterface) ->List[int]:
    return ii.do_stuffB(4)
    
print(fun(InterfaceImpl()))