Unexpected LOCF object initialization

[WenjieDu]

1. System Info

PyPOTS v0.3.1

2. Information

• The official example scripts
• My own created scripts

3. Reproduction

Initialize any model using the GRU-D data class.

4. Expected behavior

An LOCF gets initialized in the GRU-D data class.

PyPOTS/pypots/classification/grud/data.py

Line 52 in 3ff6887

self.locf = LOCF()

When the data class is initialized, no arguments will be passed into the LOCF class init func. Hence it will raise an alert and use the default device to operate LOCF.