Function key_holder_prefix 

pub fn key_holder_prefix<V: Source + Sink>(
    ast: &Ast,
    request: &ProbeRequest,
    bytes: &[u8],
) -> Result<(V, usize), ProbeError>

Decode a PLAIN_CDR2-BE holder from the start of bytes and say how many octets it took; what follows is the caller’s (DDSI-RTPS 2.5 §9.6.4.8 Step 5.1: a KeyHash is the holder padded with zeros to 16 octets).

Errors

Unsupported key context or a malformed holder.