/**
 * Adds a unique `Symbol` to the `userData` object. Use with `extractClosestEdge()` for type safe lookups.
 */
export function attachClosestEdge(userData: any, _ref: any): any;
/**
 * Returns the value added by `attachClosestEdge()` to the `userData` object. It will return `null` if there is no value.
 */
export function extractClosestEdge(userData: any): any;