input.append((char) i);
      expected.append("[" + i + "]");
    }
    assertThat(SIMPLE_ESCAPER.escape(input.toString())).isEqualTo(expected.toString());
  }

  public void testSurrogatePairs() {
    UnicodeEscaper e = SIMPLE_ESCAPER;

    // Build up a range of surrogate pair characters to test
    int min = Character.MIN_SUPPLEMENTARY_CODE_POINT;
    int max = Character.MAX_CODE_POINT;