Function put_nullable_array_len 

pub fn put_nullable_array_len<B: BufMut>(
    buf: &mut B,
    len: Option<usize>,
    flexible: bool,
) -> Result<(), ProtocolError>

Writes a nullable array-length prefix. None encodes as −1 for non-flexible versions, or 0 for flexible versions.

Errors

Returns ProtocolError::LengthOverflow when the length does not fit the prefix.