code: @Deprecated
      public int findIn(CharSequence value, int fromIndex, boolean findNot) {
          //TODO add strings, optimize, using ICU4C algorithms
          int cp;
          for (; fromIndex < value.length(); fromIndex += UTF16.getCharCount(cp)) {
              cp = UTF16.charAt(value, fromIndex);
              if (contains(cp) != findNot) {
                  break;
              }
          }
          return fromIndex;
      }
docs: Find the first index at or after fromIndex where the UnicodeSet matches at that index.
  If findNot is true, then reverse the sense of the match: find the first place where the UnicodeSet doesn't match.
  If there is no match, length is returned.
  @deprecated This API is ICU internal only. Use span instead.
  @hide original deprecated declaration
  @hide draft / provisional / internal are hidden on Android