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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 get_integration(self, name_or_class):
 # type: (Union[str, Integration]) -> Any """Returns the integration for this hub by name or class. If there is no client bound or the client does not have that integration then `None` is returned. If the return value is not `None` the hub is guaranteed to have a client attached. """

        if isinstance(name_or_class, str):
            integration_name = name_or_class
        elif name_or_class.identifier is not None:
            integration_name = name_or_class.identifier
        else:
            raise ValueError("Integration has no name")

        client = self._stack[-1][0]
        if client is not None:
            rv = client.integrations.get(integration_name)
            if rv is not None:
                return rv

        initial_client = _initial_client
        if initial_client is not None:
            initial_client = initial_client()

        if (
            initial_client is not None
            and initial_client is not client
            and initial_client.integrations.get(name_or_class) is not None
        ):
            warning = (
                "Integration %r attempted to run but it was only "
                "enabled on init() but not the client that "
                "was bound to the current flow.  Earlier versions of "
                "the SDK would consider these integrations enabled but "
                "this is no longer the case." % (name_or_class,)
            )
            warn(Warning(warning), stacklevel=3)
            logger.warning(warning)