function onFilter( error, names ) {
		if ( error ) {
			debug( 'Encountered an error when filtering packages: %s', error.message );
			return clbk( error );
		}
		debug( 'Successfully filtered packages.' );

		debug( 'Packages: %s', names.join( ', ' ) );
		clbk( null, names );
	}
Callback invoked after filtering packages.

@private
@param {(Error|null)} error - error object
@param {(EmptyArray|StringArray)} names - list of package names
@returns {void}