/**
 * Typescript aware null check. Makes sure type is narrowed when used in an array filter.
 *
 * @template T The type of the non-null items in the array.
 * @param {T | null} item The item to check for null.
 * @returns {item is T} A type predicate indicating whether the item is not null.
 *
 * @example
 * const mixedArray = [1, null, 2, null, 3];
 * const nonNullArray = mixedArray.filter(isNotNull);
 * // nonNullArray will be [1, 2, 3]
 */
export declare const isNotNull: <T>(item: T | null) => item is T;