Function try_coerce_scalar 

fn try_coerce_scalar<T, R>(
    value: T,
    from: &'static str,
    to: &'static str,
) -> Result<R, StorageCoerceError>
where
    T: TryCoerce<R>,
    T::Error: Into<CoerceErrorKind>,

Try to coerce a scalar value, mapping CoerceError to StorageCoerceError.