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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def find_cc(arch, args, sp_delta):
 """ Pinpoint the best-fit calling convention and return the corresponding SimCC instance, or None if no fit is found. :param Arch arch: An ArchX instance. Can be obtained from archinfo. :param list args: A list of arguments. :param int sp_delta: The change of stack pointer before and after the call is made. :return: A calling convention instance, or None if none of the SimCC subclasses seems to fit the arguments provided. :rtype: SimCC or None """

        if arch.name not in CC:
            return None
        possible_cc_classes = CC[arch.name]
        for cc_cls in possible_cc_classes:
            if cc_cls._match(arch, args, sp_delta):
                return cc_cls(arch, args=args, sp_delta=sp_delta)
        return None