@SuppressWarnings("ConstantCaseForConstants")
  private static final Map<Class<?>, Class<?>> PRIMITIVE_TO_WRAPPER_TYPE;

  /** A map from wrapper types to their corresponding primitive types. */
  // It's a constant, and we can't use ImmutableMap here without creating a circular dependency.
  @SuppressWarnings("ConstantCaseForConstants")
  private static final Map<Class<?>, Class<?>> WRAPPER_TO_PRIMITIVE_TYPE;

    for (Character c : map.keySet()) {
      replacements[c] = map.get(c).toCharArray();
    }
    return replacements;
  }

  // Immutable empty array for when there are no replacements.
  @SuppressWarnings("ConstantCaseForConstants") // An empty array is a constant.
  private static final char[][] EMPTY_REPLACEMENT_ARRAY = new char[0][0];

    for (Character c : map.keySet()) {
      replacements[c] = map.get(c).toCharArray();
    }
    return replacements;
  }

  // Immutable empty array for when there are no replacements.
  @SuppressWarnings("ConstantCaseForConstants") // An empty array is a constant.
  private static final char[][] EMPTY_REPLACEMENT_ARRAY = new char[0][0];