Custom dataset gin file

I have followed [this](https://github.com/google-research/t5x#custom-components) section to create my own dataset and run the `train.py` script. However, I get the following error:
```
ModuleNotFoundError: No module named 'tasks'
In file "/root/dir1/user_dir/t5_1_1_base_custom_v1.gin", line 2
import tasks
```
Any help would be appreciated!