HeadersWith creates a copy of headers with newHeader=newValue.

New returns a new Fetcher for parallel downloads.

DefaultUserAgent is the HTTP user agent string.

DefaultConnectTimeout is how long to wait for a connection to timeout.

DefaultHTTPClient is the default HTTP client to use for requests.

DefaultHTTPTransport is the default transport to use for HTTP requests.

DefaultReadTimeout is how long to wait for a HTTP read to timeout.

A Fetcher downloads files from remote servers.

A FetchRequest is a request to download URL to Filename.

A FetchResult is the result of a fetch.

An HTTPError represents a HTTP status code and the server's response.

Headers is a map of HTTP headers.