/**
 * Merges a partial object with a fallback object, deeply combining the two.
 *
 * @param {Partial<T>} partial - the partial object to merge (can be undefined)
 * @param {T} fallback - the fallback object to merge with
 * @return {T} the merged object
 */
export declare function deepMerge<T>(partial: Partial<T> | undefined, fallback: T): T;