BatchCreate: Creates one or more new annotations atomically. All annotations must belong to the same annotation set. Caller must have WRITE permission for this annotation set. For optimal performance, batch positionally adjacent annotations together. If the request has a systemic issue, such as an attempt to write to an inaccessible annotation set, the entire RPC will fail accordingly. For lesser data issues, when possible an error will be isolated to the corresponding batch entry in the response; the remaining well formed annotations will be created normally. For details on the requirements for each individual annotation resource, see CreateAnnotation.