pub fn encode_unknown_size(len: u8, out: &mut Vec<u8>)Expand description
Write the reserved “unknown size” VINT of length len (1..=8) into out
— all VINT_DATA bits set to 1, marker bit set.
Used for a Segment mux writes as always-unknown-size (streaming: total
length isn’t known upfront). len outside 1..=8 clamps rather than
panics (this crate only ever calls it with the literal 4; kept total
for a public fn).