public void testPadEnd_null() {
    try {
      Strings.padEnd(null, 5, '0');
      fail();
    } catch (NullPointerException expected) {
    }
  }

  public void testRepeat() {
    String input = "20";
    assertEquals("", Strings.repeat(input, 0));
    assertEquals("20", Strings.repeat(input, 1));
    assertEquals("2020", Strings.repeat(input, 2));

			_ = Concat(ss...)
		}()
		if didPanic := r != nil; didPanic != tc.shouldPanic {
			t.Errorf("slices.Concat(lens(%v)) got panic == %v",
				tc.lengths, didPanic)
		}
	}
}

func TestRepeat(t *testing.T) {
	// normal cases
	for _, tc := range []struct {
		x     []int
		count int
		want  []int
	}{
		{x: []int(nil), count: 0, want: []int{}},
		{x: []int(nil), count: 1, want: []int{}},