Expose the options so that users can customize their cache key generation if they really need it.

[Nilabhra]

          >> It'll be better if there is a default way to generate the cache key since it is not natural that users must configure how to generate the cache key after they set cache=True. But it makes sense to expose the options so that users can customize their cache key generation if they really need it.

For example, if cache=True, then the cache key will be associated with the function signature and parameter values. But users can choose which parameter value to ignore.

I totally agree with this but it might take a while to get this working. How about we create an issue and resolve this in a separate PR?

@nikhilranjan7 Sure. Let's create an issue to keep track of this after this PR is merged.

Originally posted by @zhanyuanucb in #27 (comment)