code: public static CalibrationDetectorCircleHexagonalGrid circleHexagonalGrid( @Nullable ConfigCircleHexagonalGrid config ,
  																			 ConfigGridDimen configGrid ) {
  		if( config == null )
  			config = new ConfigCircleHexagonalGrid();
  		config.checkValidity();
  
  		return new CalibrationDetectorCircleHexagonalGrid(config,configGrid);
  	}
docs: Detector for hexagonal grid of circles.  All circles must be entirely inside of the image.
  
  @param config Configuration for target
  @return The detector