/**
 * A collection of key-value pairs.
 * @extends Map
 */
export declare class Collection<T extends string | number | symbol, V> extends Map<T, V> {
    /**
     * Creates a new collection.
     * @param entries The entries to set in the collection.
     */
    constructor(entries?: readonly (readonly [T, V])[] | null);
    /**
     * Finds the first value that satisfies the condition.
     * @param fn The function to execute.
     * @returns Returns the value if found, otherwise undefined.
     */
    find(fn: (value: V, key: T, collection: this) => boolean): V | undefined;
    /**
     * Filters the collection by a condition.
     * @param fn The function to execute.
     * @returns The filtered collection.
     */
    filter(fn: (value: V, key: T, collection: this) => boolean): Collection<T, V>;
    /**
     * Maps the collection.
     * @param fn The function to execute.
     * @returns The mapped collection.
     */
    map<T2>(fn: (value: V, key: T, collection: this) => T2): Collection<T, T2>;
    /**
     * Checks if any value satisfies the condition.
     * @param fn The function to execute.
     * @returns Whether any value satisfies the condition.
     */
    some(fn: (value: V, key: T, collection: this) => boolean): boolean;
    /**
     * Checks if every value satisfies the condition.
     * @param fn The function to execute.
     * @returns Whether every value satisfies the condition.
     */
    every(fn: (value: V, key: T, collection: this) => boolean): boolean;
    /**
     * Reduces the collection to a single value.
     * @param fn The function to execute.
     * @param initial The initial value.
     * @returns The reduced value.
     */
    reduce<T2>(fn: (accumulator: T2, value: V, key: T, collection: this) => T2, initial: T2): T2;
    /**
     * Returns the first value of the collection.
     * @returns The first value of the collection.
     */
    first(): V | undefined;
    /**
     * Transform the collection into an array containing the values of it.
     * @returns The array containing the values of the collection.
     */
    toArray(): V[];
}