Function encode_string 

pub fn encode_string<B>(
    dst: &mut B,
    data: &[u8],
    prefix_bits: u8,
    flags: u8,
    huffman: bool,
)
where
    B: BufMut,

Available on crate features http and std only.

Encode a string literal with an prefix_bits-bit length prefix (RFC 9204 §4.1.2).

flags occupies the bits above the Huffman bit; the Huffman bit itself is bit prefix_bits.