docs: public <R> MapPartitionOperator<T, R> mapPartition(MapPartitionFunction<T, R> mapPartition) {
  		if (mapPartition == null) {
  			throw new NullPointerException("MapPartition function must not be null.");
  		}
  
  		String callLocation = Utils.getCallLocationName();
  		TypeInformation<R> resultType = TypeExtractor.getMapPartitionReturnTypes(mapPartition, getType(), callLocation, true);
  		return new MapPartitionOperator<>(this, resultType, clean(mapPartition), callLocation);
  	}