Given the following code snippet, identify the bug that breaks the Chain of Responsibility pattern:

Given the following code snippet, identify the bug that breaks the Chain of Responsibility pattern:

class Handler:
    def __init__(self, successor=None):
        self.successor = successor
    def handle(self, request):
        if self.can_handle(request):
            return f"Handled {request}"
        else:
            return "Not handled"
    def can_handle(self, request):
        return False

class ConcreteHandler(Handler):
    def can_handle(self, request):
        return request == 'X'

chain = ConcreteHandler()
print(chain.handle('Y'))

What is the main issue here?