code: function verifyArguments( args ) {
  	if ( ! isObject( args.callbacks.getData ) ) {
  		throw new MissingArgument( "The app requires an object with a getdata callback." );
  	}
  
  	if ( ! isObject( args.targets ) ) {
  		throw new MissingArgument( "`targets` is a required App argument, `targets` is not an object." );
  	}
  
  	// The args.targets.snippet argument is only required if not SnippetPreview object has been passed.
  	if (
  		args.hasSnippetPreview &&
  		! isValidSnippetPreview( args.snippetPreview ) &&
  		! isString( args.targets.snippet ) ) {
  		throw new MissingArgument( "A snippet preview is required. When no SnippetPreview object isn't passed to " +
  			"the App, the `targets.snippet` is a required App argument. `targets.snippet` is not a string." );
  	}
  }
docs: Check arguments passed to the App to check if all necessary arguments are set.
  
  @private
  @param {Object}      args            The arguments object passed to the App.
  @returns {void}