Although technically supported by the API, there is no valid reason that an integrating developer needs to make a request with zero ad types. That will always return an empty list of decisions. So to make it less likely that someone will accidentally programmatically send us an empty list, or just not know and send us an empty list, let's require at least one ad type. The Android and Swagger-generated SDKs already handle this case.
Acceptance Criteria
Give a clear, easy-to-understand message similar to "Each placement requires at least one ad type" if there are no ad types on a given placement.
Background
Although technically supported by the API, there is no valid reason that an integrating developer needs to make a request with zero ad types. That will always return an empty list of decisions. So to make it less likely that someone will accidentally programmatically send us an empty list, or just not know and send us an empty list, let's require at least one ad type. The Android and Swagger-generated SDKs already handle this case.
Acceptance Criteria