Auth
Creates a new #SoupAuth of type @type with the information from
Return
the new #SoupAuth, or null if it could not be created
Parameters
type
the type of auth to create (a subtype of #SoupAuth)
msg
the #SoupMessage the auth is being created for
authHeader
the WWW-Authenticate/Proxy-Authenticate header
constructor(pointer: <Error class: unknown class><<Error class: unknown class>>)