code: public void setFileExtension(String modelFileExtension) {
  		if (modelFileExtension == null || "".equals(modelFileExtension.trim())) {
  			return;
  		}
  		this.modelFileExtension = modelFileExtension.trim();
  	}
docs: Sets the file extension used when creating the initial sample model.
  
  @param modelFileExtension
  @since 2.4