def get_events(subscription_id, watermark)
      req = build_soap! do |type, builder|
        if(type == :header)
        else
          builder.nbuild.GetEvents {
            builder.nbuild.parent.default_namespace = @default_ns
            builder.subscription_id!(subscription_id)
            builder.watermark!(watermark, NS_EWS_MESSAGES)
          }
        end
      end
      do_soap_request(req, response_class: EwsResponse)
    end
def get_events(subscription_id, watermark)
      req = build_soap! do |type, builder|
        if(type == :header)
        else
          builder.nbuild.GetEvents {
            builder.nbuild.parent.default_namespace = @default_ns
            builder.subscription_id!(subscription_id)
            builder.watermark!(watermark, NS_EWS_MESSAGES)
          }
        end
      end
      do_soap_request(req, response_class: EwsResponse)
    end
Used by pull subscription clients to request notifications from the Client Access server
 @see http://msdn.microsoft.com/en-us/library/aa566199.aspx GetEvents on MSDN

 @param [String] subscription_id Subscription identifier
 @param [String] watermark Event bookmark in the events queue