Method declaration column-indented

core.ts

/**
 * Filters an array by a predicate function. Returns the same array instance if the predicate is
 * true for all elements, otherwise returns a new array instance containing the filtered subset.
 */
export function filter<T, U extends T>(array:               T[], f: (x: T) => x is U ): U[];
export function filter<T             >(array:               T[], f: (x: T) => boolean): T[];
export function filter<T, U extends T>(array: ReadonlyArray<T> , f: (x: T) => x is U ): ReadonlyArray<U>;
export function filter<T, U extends T>(array: ReadonlyArray<T> , f: (x: T) => boolean): ReadonlyArray<T>;
export function filter<T             >(array:               T[], f: (x: T) => boolean): T[] {
    if (array) {
        const len = array.length;
        let i = 0;
        // ...