Initial implementation of required functionality

[e-sumin]

Implementing functionality proposed in design proposal #2

[hairyhum]

There are some questions about usage and documenting less obvious behaviour.

[denisvmedia]

I see another draft PR merged without changing the title and putting the description. Can we please improve the title and the desc here before we merge it?

[hairyhum]

I see another draft PR merged without changing the title and putting the description. Can we please improve the title and the desc here before we merge it?

@e-sumin yes, can we get the final version in a single PR?

[hairyhum]

This function is only called in the test as I understand.
Is there some other use for it?
If not, should it be moved to the test or maybe test helper file?

[e-sumin]

Thanks for pointing, in last commit I've extracted part which is common for marshalling code and for tests, and removed all irrelevant things.

Please re-review this commit.

[hairyhum]

LGTM apart from internal/caller/frame.go file.

[hairyhum]

LGTM