Identify a pulling Messaging Gateway method as an Outbound Channel Adapter EI pattern.

[artembilan]

See https://docs.spring.io/spring-integration/reference/html/messaging-endpoints.html#gateway-calling-no-argument-methods

When invoking methods on a Gateway interface that do not have any arguments, the default behavior is to receive a Message from a PollableChannel.

In this case a Messaging Gateway components is going to be present in the end of flow.

[artembilan]

Fixed via: bc8e775