TestCharSource okSource = new TestCharSource(STRING);
    assertThrows(IOException.class, () -> okSource.copyTo(new TestWriter(WRITE_THROWS)));
    assertTrue(okSource.wasStreamClosed());
  }

  public void testConcat() throws IOException {
    CharSource c1 = CharSource.wrap("abc");
    CharSource c2 = CharSource.wrap("");
    CharSource c3 = CharSource.wrap("de");

    String expected = "abcde";

    OutputStream out = new TestOutputStream(ByteStreams.nullOutputStream(), WRITE_THROWS);
    assertThrows(IOException.class, () -> okSource.copyTo(out));
    assertTrue(okSource.wasStreamClosed());
  }

  public void testConcat() throws IOException {
    ByteSource b1 = ByteSource.wrap(new byte[] {0, 1, 2, 3});
    ByteSource b2 = ByteSource.wrap(new byte[0]);
    ByteSource b3 = ByteSource.wrap(new byte[] {4, 5});

	}

	type S []int
	s2 := S{4, 5, 6}
	apply(s2, Reverse)
	if want := (S{6, 5, 4}); !Equal(s2, want) {
		t.Errorf("Reverse(%v) = %v, want %v", S{4, 5, 6}, s2, want)
	}
}

func TestConcat(t *testing.T) {
	cases := []struct {
		s    [][]int
		want []int
	}{
		{
			s:    [][]int{nil},
			want: nil,
		},
		{
			s:    [][]int{{1}},
			want: []int{1},
		},

  func.return %0 : tensor<1x4x384x384xf32>
}

// -----

func.func @testConcat(%arg0: tensor<1x2xi32>, %arg1: tensor<1x2xi32>) -> tensor<2x2xi32> {
  // CHECK: "tfl.concatenation"(%arg0, %arg1) <{axis = 0 : i32, fused_activation_function = "NONE"}>