*
   * <ul>
   *   <li>The alphanumeric characters "a" through "z", "A" through "Z" and "0" through "9" remain
   *       the same.
   *   <li>The special characters ".", "-", "*", and "_" remain the same.
   *   <li>The space character " " is converted into a plus sign "+".
   *   <li>All other characters are converted into one or more bytes using UTF-8 encoding and each

    }

    /**
     * Strips invalid XML characters from the input string.
     *
     * This method removes characters that are not allowed in XML documents
     * according to the XML 1.0 specification. Valid characters include:
     * - Tab (0x9)
     * - Line feed (0xA)
     * - Carriage return (0xD)
     * - Any character between 0x20 and 0xD7FF
     * - Any character between 0xE000 and 0xFFFD

  }

  @Override
  RowSortedTable<String, Integer, Character> makeTable() {
    RowSortedTable<String, Integer, Character> original = TreeBasedTable.create();
    return unmodifiableRowSortedTable(original);
  }

  @Override
  protected SortedMap<String, Map<Integer, Character>> makePopulatedMap() {
    RowSortedTable<String, Integer, Character> table = TreeBasedTable.create();
    table.put("foo", 1, 'a');

    assertFalse(table.containsValue(null));
  }

  public void testGet() {
    table = create("foo", 1, 'a', "bar", 1, 'b', "foo", 3, 'c');
    assertEquals((Character) 'a', table.get("foo", 1));
    assertEquals((Character) 'b', table.get("bar", 1));
    assertEquals((Character) 'c', table.get("foo", 3));
    assertNull(table.get("foo", 2));
    assertNull(table.get("bar", 3));
    assertNull(table.get("cat", 1));

    Table<Integer, String, Character> original = HashBasedTable.create();
    Table<String, Integer, Character> transpose = transpose(original);
    transpose.put("foo", 1, 'a');
    assertEquals((Character) 'a', original.get(1, "foo"));
  }

  public void testTransposedViews() {
    Table<Integer, String, Character> original = HashBasedTable.create();
    Table<String, Integer, Character> transpose = transpose(original);

    // need explicit type parameter to avoid javac warning!?
    List<Character> none = Arrays.<Character>asList();
    assertThat(Chars.toArray(none)).isEqualTo(EMPTY);

    List<Character> one = Arrays.asList((char) 1);
    assertThat(Chars.toArray(one)).isEqualTo(ARRAY1);

    char[] array = {(char) 0, (char) 1, 'A'};

    List<Character> three = Arrays.asList((char) 0, (char) 1, 'A');

    }

    /**
     * Gets the character set for the given file.
     *
     * @param file the file to get the character set for
     * @return the character set
     */
    protected String getCharSet(final File file) {
        return charset;
    }

    /**
     * Gets the character encoding used for files.
     *
     * @return the character encoding
     */
    public String getCharset() {

import static com.google.common.truth.Truth.assertThat;
import static java.lang.Character.MAX_CODE_POINT;
import static java.lang.Character.MAX_HIGH_SURROGATE;
import static java.lang.Character.MAX_LOW_SURROGATE;
import static java.lang.Character.MIN_HIGH_SURROGATE;
import static java.lang.Character.MIN_LOW_SURROGATE;
import static java.lang.Character.MIN_SUPPLEMENTARY_CODE_POINT;
import static java.nio.charset.StandardCharsets.UTF_8;

      if (prefix.exhausted()) {
        break
      }
      val codePoint = prefix.readUtf8CodePoint()
      if (Character.isISOControl(codePoint) && !Character.isWhitespace(codePoint)) {
        return false
      }
    }
    return true
  } catch (_: EOFException) {
    return false // Truncated UTF-8 sequence.
  }

  }

  public void testEmptyMap() {
    Map<Character, String> map = ImmutableMap.of();
    ArrayBasedEscaperMap fem = ArrayBasedEscaperMap.create(map);
    // Non-null array of zero length.
    assertThat(fem.getReplacementArray()).isEmpty();
  }

  public void testMapLength() {
    Map<Character, String> map =
        ImmutableMap.of(
            'a', "first",
            'z', "last");