What happens when Python's self keyword is invoked as a function like self(**inputs)?

I was reading through some code and stumbled into this line of code, see the link below.
Can someone explain what's going on here? Does this call the constructor? I've never seen self used in such a way before.

outputs = self(**model_inputs)

https://github.com/huggingface/transformers/blob/aa925a52fad9d6b98dac4c1b27f881bef7e88dad/src/transformers/modeling_utils.py#L1223