Create `ErrApplyBlock` with `Unwrap` method.

[tzdybal]

          Create `ErrApplyBlock` with `Unwrap` method.

Originally posted by @tzdybal in #643 (comment)

[raadhshenshahhaseeb]

@tzdybal Hi, if this issue is still open, can I work on it?

[MSevey]

hey @raadhshenshahhaseeb
this issues is actually a little outdated, I just removed the good first issue label since this refers to code that is no longer on the main branch, but on a separate branch that we will come back to in the future.

So I wouldn't recommend working on this at the moment.