from typing import Protocol


class Shape(Protocol):
    def area(self) -> str:
        ...


class Circle:
    def area(self) -> str:
        return 'π * r²'


class Square:
    def area(self) -> str:
        return 'w * l'


class ShapeFactory:
    def create(self, shape_type: str) -> Shape:
        return Circle() if shape_type == 'circle' else Square()  # Here

# ... code omitted

class ShapeFactory:
    def create(self, shape_type: str) -> Shape:
        if shape_type == 'circle':
            return Circle()
        else:
            return Square()