@ValidationMethod(message = "loaderPipeline docRef must have a UUID")
        @JsonIgnore
        public boolean isValidLoaderDocRef() {
            return loaderPipeline != null && loaderPipeline.getUuid() != null && !loaderPipeline.getUuid().isEmpty();
        }
@return data string or epoch ms
stroom-pipeline/src/main/java/stroom/pipeline/refdata/RefDataLookupRequest.java