closes#1324
#### Problem
Currently, it is possible to accidentally use inner unversioned
migration instead of `VersionedMigration` since both implement
`OnRuntimeUpgrade`.
#### Solution
With this change, we make it clear that value of `Inner` is not intended
to be used directly. It is achieved by bounding `Inner` to new trait
`UncheckedOnRuntimeUpgrade`, which has the same interface (except
`unchecked_` prefix) as `OnRuntimeUpgrade`.
#### `try-runtime` functions
Since developers can implement `try-runtime` for `Inner` value in
`VersionedMigration` and have custom logic for it, I added the same
`try-runtime` functions to `UncheckedOnRuntimeUpgrade`. I looked for a
ways to not duplicate functions, but couldn't find anything that doesn't
significantly change the codebase. So I would appreciate If you have any
suggestions to improve this
cc @liamaharon @xlc
polkadot address: 16FqwPZ8GRC5U5D4Fu7W33nA55ZXzXGWHwmbnE1eT6pxuqcT
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Co-authored-by: Liam Aharon <liam.aharon@hotmail.com>
The FRAME development environment provides modules (called "pallets") and support libraries that you can use, modify,
and extend to build the runtime logic to suit the needs of your blockchain.
Dastan
e54279699b