Function decode 

pub fn decode<T>(
    res: Result<Option<(Cow<'_, [u8]>, Cow<'_, [u8]>)>, impl Into<DatabaseErrorInfo>>,
) -> PairResult<T>
where
    T: Table,
    T::Key: Decode,
    T::Value: Decompress,

Available on crate feature mdbx only.

Decodes a (key, value) pair from the database.