in lambda-http/src/response.rs [97:106]
fn serialize_headers_slice<S>(headers: &[HeaderValue], serializer: S) -> Result<S::Ok, S::Error>
where
S: Serializer,
{
let mut seq = serializer.serialize_seq(Some(headers.len()))?;
for header in headers {
seq.serialize_element(header.to_str().map_err(S::Error::custom)?)?;
}
seq.end()
}