Where is the definition of eval?

Where is the definition of eval?
[DEKR](https://github.com/HRNet/DEKR)/[lib](https://github.com/HRNet/DEKR/tree/main/lib)/[dataset](https://github.com/HRNet/DEKR/tree/main/lib/dataset)/build.py /    
dataset = eval(cfg.DATASET.DATASET)(
        cfg,
        cfg.DATASET.TRAIN,
        heatmap_generator,
        offset_generator,
        transforms
    )