Stores credential parameters into the store.

        :param correlation_id: (optional) transaction id to trace execution through call chain.

        :param key: a key to uniquely identify the credential parameters.

        :param credential: a credential parameters to be stored.

def store(self, correlation_id, key, credential):
        """
        Stores credential parameters into the store.

        :param correlation_id: (optional) transaction id to trace execution through call chain.

        :param key: a key to uniquely identify the credential parameters.

        :param credential: a credential parameters to be stored.
        """
        if credential != None:
            self._items.put(key, credential)
        else:
            self._items.remove(key)