Android蓝牙低功耗：characteristic.getPermissions（）返回0？

I am writing an Android BLE application, and I am trying to get the permissions of a certain characteristic. I have already managed to get the characteristic properties with characteristic.getProperties(), and it returns a non-zero value, however, when I use the getPermission() method it returns 0 even though I am sure that the characteristic has PERMISSION_WRITE_ENCRYPTED_MITM (0x00000040).I am writing an Android BLE application, and I