code: function start(config) {
  		if (!isConfigurationParametersDefinedCorrectly(config)) {
  			throw new Error('license-check - Configuration error');
  		}
  
  		var folders = [];
  		if (config.src) {
  			folders = getFoldersToCheck(config.src);
  		}
  
  		if (folders.length === 0) {
  			gutil.log('license-check', gutil.colors.red('{src} not defined or empty, the plugin will run with the default configuration: **/*'));
  			folders = getDefaultFolders();
  		}
  
  		var src = vfs.src(folders);
  		src.pipe(license(config));
  		return src;
  	}
docs: Main execution function
  
  @returns {object} return the stream to make possible append pipe or listen on channel such on('data') on('error) .