=== tests/cases/compiler/arrayAugment.ts ===
interface Array<T> {
>Array : T[]
>T : T

    split: (parts: number) => T[][];
>split : (parts: number) => T[][]
>parts : number
>T : T
}

var x = [''];
>x : string[]
>[''] : string[]

var y = x.split(4);
>y : string[][]
>x.split(4) : string[][]
>x.split : (parts: number) => string[][]
>x : string[]
>split : (parts: number) => string[][]

var y: string[][]; // Expect no error here
>y : string[][]