Http_types.HeadersThe `t` type, represents a list of HTTP headers as a list of key-value pairs.
add ~key ~value h creates a new list of headers by adding a new header with the given key key and value value to the list of headers h.
with_host headers host creates a new list of headers by adding a "Host" header with the given value host to the list of headers headers.
with_content_length headers len creates a new list of headers by adding a "Content-Length" header with the given value len to the list of headers headers.
with_host_of_uri headers url creates a new list of headers by adding a "Host" header with the host and port from the given URL url to the list of headers headers.