Struct Channels 

#[non_exhaustive]
pub struct Channels(_, pub C1, pub C2, pub C3, pub C4, pub C5);

Tuple Fields (Non-exhaustive)

Non-exhaustive structs could have additional fields added in future. Therefore, non-exhaustive structs cannot be constructed in external crates using the traditional Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.

1: C1

2: C2

3: C3

4: C4

5: C5