def build_passwordless_session(authenticatable)
      Session.new.tap do |us|
        us.remote_addr = request.remote_addr
        us.user_agent = request.env["HTTP_USER_AGENT"]
        us.authenticatable = authenticatable
      end
    end
def build_passwordless_session(authenticatable)
      Session.new.tap do |us|
        us.remote_addr = request.remote_addr
        us.user_agent = request.env["HTTP_USER_AGENT"]
        us.authenticatable = authenticatable
      end
    end
Build a new Passwordless::Session from an _authenticatable_ record.
 Set's `user_agent` and `remote_addr` from Rails' `request`.
 @param authenticatable [ActiveRecord::Base] Instance of an
   authenticatable Rails model
 @return [Session] the new Session object
 @see ModelHelpers#passwordless_with