How files in checkpoint are created ?

I am working on a problem that my dataset is divided in subsets of 10. So what i need to do is train each subset of data with few epoches then stop training and again start the training process by replacing the previous subset of data with new one. Now the problem is that in the final or last model file in checkpoint does not contain any information of training data of previous subsets of dataset i trained it on but contain information on only the subset of dataset i trained at the end ........ So my question is ... Isn't model file should contain all info of all subsets of dataset i trained on?

The problem is related to additional training on already trained data...
This line in the code is saving model file in checkpoint ?
https://github.com/carpedm20/DCGAN-tensorflow/blob/351a6540d742c467a951a8f028af38b904fcdcc6/model.py#L317

Start at model.py line 317, which the issue identifies as the checkpoint save site, and trace how checkpoints are written and restored during additional training. Compare checkpoint handling across successive dataset subsets and document whether the reported expectation is supported; a useful resolution should explain what is retained and what is not.

Written by the indexing model from the issue text.