Function frame_support::storage::migration::storage_key_iter

pub fn storage_key_iter<K: Decode + Sized, T: Decode + Sized, H: ReversibleStorageHasher>(
    module: &[u8],
    item: &[u8]
) -> PrefixIterator<(K, T)> 

Construct iterator to iterate over map items in module for the map called item.