GetRangeStart returns the byte index of the start of the range, if it has one.

NewResponse builds new HTTP responses.

RequestHeader returns a new set of headers from a request.

ResponseHeader returns a new set of headers from a request.

Warning adds an error to the Warning header in the format: 199 "martian" "error message" "date".

Header is a generic representation of a set of HTTP headers for requests and responses.