Metrics will be collected for this message.
The AuthManager should not use
the credentials cache for this message, neither to use cached credentials
to automatically authenticate this message nor to cache the credentials
after the message is successfully authenticated. This applies to both server
and proxy authentication. Note that Soup.Message::authenticate signal will
be emitted, if you want to disable authentication for a message use
Message.disable_feature passing #SOUP_TYPE_AUTH_MANAGER instead.
The message is considered idempotent, regardless its Message.method, and allows reuse of existing idle connections, instead of always requiring a new one, unless #SOUP_MESSAGE_NEW_CONNECTION is set.
Requests that the message should be sent on a newly-created connection, not reusing an existing persistent connection. Note that messages with non-idempotent Message.methods behave this way by default, unless #SOUP_MESSAGE_IDEMPOTENT is set.
The session should not follow redirect (3xx) responses received by this message.
Various flags that can be set on a Message to alter its behavior.