/**
 * @description converts tokens to type and returns array with used type
 * @param tree object
 * @param callback function to be run on valid items
 * @param validItem function to test if a node is a validItem to be transformed
 * @returns object
 */
export declare const treeWalker: (tree: unknown, callback: <T>(argument: T) => unknown, isValidItem: (argument: unknown) => boolean) => unknown;