def auth_type=(type=:basic)
      @auth_type = case type
      when :basic, "basic"
        Request::AuthBasic
      when :digest, "digest"
        Request::AuthDigest
      when :any, "any"
        Request::AuthAny
      else
        raise "#{type.inspect} is an unknown authentication type"
      end
    end
def auth_type=(type=:basic)
      @auth_type = case type
      when :basic, "basic"
        Request::AuthBasic
      when :digest, "digest"
        Request::AuthDigest
      when :any, "any"
        Request::AuthAny
      else
        raise "#{type.inspect} is an unknown authentication type"
      end
    end
Set the type of authentication to use for this request.

 @param [String, Symbol]type The type of authentication to use for this request, can be one of
   :basic, :digest, or :any

 @example
   sess.username = "foo"
   sess.password = "sekrit"
   sess.auth_type = :digest