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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_usb_controller_count_by_type(self, type_p):
 """Returns the number of USB controllers of the given type attached to the VM. in type_p of type :class:`USBControllerType` return controllers of type int """

        if not isinstance(type_p, USBControllerType):
            raise TypeError("type_p can only be an instance of type USBControllerType")
        controllers = self._call("getUSBControllerCountByType",
                     in_p=[type_p])
        return controllers