function Loader( model, config ) {

	/**
	 * Store model context.
	 *
	 * { Object }, model context
	 */

	this.model = model;

	/**
	 * Store loader config.
	 *
	 * { JSON }, user's configuration for loader.
	 */

	this.config = config;

	/**
	 * Store callback function fired when model load process is completed.
	 *
	 * @type { function }
	 */

	this.onCompleteCallback = undefined;
	
	/**
	 * Store callback function fired periodically before load process is completed.
	 *
	 * @type { function }
	 */
	
	this.onProgressCallBack = undefined;
	
	/**
	 * Tfjs LoadOption object.
	 *
	 * @type { Object }
	 */
	
	this.tfjsLoadOption = {};

	// Load loader's basic configuration.

	this.loadLoaderConfig( config );

}
Abstract Class, can not be initialized by TensorSpace user.
Load model from dependent library, for example, keras, tfjs, tensorflow.

Base class for KerasLoader, TfjsLoader, TfLoader.

@param model, model context
@param config, user's configuration for loader
@constructor