in geronimo-openapi-impl/src/main/java/org/apache/geronimo/microprofile/openapi/impl/model/ComponentsImpl.java [103:108]
public Components addCallback(final String key, final Callback _callbacks) {
if (_callbacks != null) {
(this._callbacks = this._callbacks == null ? new LinkedHashMap<>() : this._callbacks).put(key, _callbacks);
}
return this;
}