private void createPublishBindings(
            OperationIndex operationIndex,
            OperationShape operation,
            PublishTrait trait
    ) {
        StructureShape input = operationIndex.expectInputShape(operation);
        TopicBinding<PublishTrait> topicBinding = new TopicBinding<>(operation, trait, trait.getTopic(), input, input);
        publishBindings.put(operation.getId(), topicBinding);
    }
Get subscribe event stream info.

<p>This information describes if the event stream contains a single
event, multiple events, and if there are any initial-request or
response members.

@param operation Operation to get the event stream info o.
@return Returns the optionally found event stream info.
smithy-mqtt-traits/src/main/java/software/amazon/smithy/mqtt/traits/ResolvedTopicIndex.java