code: @Deprecated
      public static int decompose(char[] src,int srcStart, int srcLimit,
                                  char[] dest,int destStart, int destLimit,
                                  boolean compat, int options) {
          CharBuffer srcBuffer = CharBuffer.wrap(src, srcStart, srcLimit - srcStart);
          CharsAppendable app = new CharsAppendable(dest, destStart, destLimit);
          getDecomposeNormalizer2(compat, options).normalize(srcBuffer, app);
          return app.length();
      }
docs: Decompose a string.
  The string will be decomposed to according to the specified mode.
  @param src       The char array to compose.
  @param srcStart  Start index of the source
  @param srcLimit  Limit index of the source
  @param dest      The char buffer to fill in
  @param destStart Start index of the destination buffer
  @param destLimit End index of the destination buffer
  @param compat If true the char array will be decomposed according to NFKD
  rules and if false will be decomposed according to
  NFD rules.
  @param options The normalization options, ORed together (0 for no options).
  @return int   The total buffer size needed;if greater than length of
  result,the output was truncated.
  @exception IndexOutOfBoundsException if the target capacity is less than
  the required length
  @deprecated ICU 56 Use {@link Normalizer2} instead.
  @hide original deprecated declaration