// The first character in the safe range.
  private final char safeMin;
  // The last character in the safe range.
  private final char safeMax;

  /**
   * Creates a new ArrayBasedCharEscaper instance with the given replacement map and specified safe
   * range. If {@code safeMax < safeMin} then no characters are considered safe.
   *

const (
	pC     = 1 << iota // a control character.
	pP                 // a punctuation character.
	pN                 // a numeral.
	pS                 // a symbolic character.
	pZ                 // a spacing character.
	pLu                // an upper-case letter.
	pLl                // a lower-case letter.
	pp                 // a printable character according to Go's definition.

      Character[] suffix = {(char) 86, (char) 99};
      Character[] all = concat(concat(prefix, elements), suffix);
      return asList(all).subList(2, elements.length + 2);
    }
  }

  private static Character[] concat(Character[] left, Character[] right) {
    Character[] result = new Character[left.length + right.length];
    System.arraycopy(left, 0, result, 0, left.length);

Single characters:

	.              any character, possibly including newline (flag s=true)
	[xyz]          character class
	[^xyz]         negated character class
	\d             Perl character class
	\D             negated Perl character class
	[[:alpha:]]    ASCII character class
	[[:^alpha:]]   negated ASCII character class
	\pN            Unicode character class (one-letter name)

   *
   * @param replacementMap a map of characters to their escaped representations
   * @param safeMin the lowest character value in the safe range
   * @param safeMax the highest character value in the safe range
   * @param unsafeReplacement the default replacement for unsafe characters or null if no default
   *     replacement is required
   */
  protected ArrayBasedUnicodeEscaper(
      Map<Character, String> replacementMap,
      int safeMin,

   *
   * @param replacementMap a map of characters to their escaped representations
   * @param safeMin the lowest character value in the safe range
   * @param safeMax the highest character value in the safe range
   * @param unsafeReplacement the default replacement for unsafe characters or null if no default
   *     replacement is required
   */
  protected ArrayBasedUnicodeEscaper(
      Map<Character, String> replacementMap,
      int safeMin,

 * when more than one escaper is created using the same character replacement mapping to allow the
 * underlying (implementation specific) data structures to be shared.
 *
 * <p>The size of the data structure used by ArrayBasedCharEscaper and ArrayBasedUnicodeEscaper is
 * proportional to the highest valued character that has a replacement. For example a replacement
 * map containing the single character '{@literal \}u1000' will require approximately 16K of memory.

  /**
   * Asserts that an escaper does not escape the given character.
   *
   * @param escaper the non-null escaper to test
   * @param c the character to test
   */
  public static void assertUnescaped(CharEscaper escaper, char c) {
    Assert.assertNull(computeReplacement(escaper, c));
  }

  /**
   * Asserts that a Unicode escaper does not escape the given character.
   *
   * @param escaper the non-null escaper to test

  /**
   * Asserts that an escaper does not escape the given character.
   *
   * @param escaper the non-null escaper to test
   * @param c the character to test
   */
  public static void assertUnescaped(CharEscaper escaper, char c) {
    Assert.assertNull(computeReplacement(escaper, c));
  }

  /**
   * Asserts that a Unicode escaper does not escape the given character.
   *
   * @param escaper the non-null escaper to test

 * when more than one escaper is created using the same character replacement mapping to allow the
 * underlying (implementation specific) data structures to be shared.
 *
 * <p>The size of the data structure used by ArrayBasedCharEscaper and ArrayBasedUnicodeEscaper is
 * proportional to the highest valued character that has a replacement. For example a replacement
 * map containing the single character '{@literal \}u1000' will require approximately 16K of memory.