src/vs/editor/common/model/textModelTokens.ts/ContiguousGrowingArray/insert
class ContiguousGrowingArray:	public insert(insertIndex: number, insertCount: number): void {
		if (insertCount === 0 || insertIndex >= this._store.length) {
			return;
		}
		const arr: T[] = [];
		for (let i = 0; i < insertCount; i++) {
			arr[i] = this._default;
		}
		this._store = arrays.arrayInsert(this._store, insertIndex, arr);
	}