def get_default_device(self, adb_path=None):
        """
        Get local default device when no serialno

        Returns:
            local device serialno

        """
        if not ADB(adb_path=adb_path).devices(state="device"):
            raise IndexError("ADB devices not found")
        return ADB(adb_path=adb_path).devices(state="device")[0][0]

        Get local default device when no serialno

        Returns:
            local device serialno

        
airtest/core/android/android.py