code: @Deprecated
      public boolean skeletonsAreSimilar(String id, String skeleton) {
          if (id.equals(skeleton)) {
              return true; // fast path
          }
          // must clone array, make sure items are in same order.
          TreeSet<String> parser1 = getSet(id);
          TreeSet<String> parser2 = getSet(skeleton);
          if (parser1.size() != parser2.size()) {
              return false;
          }
          Iterator<String> it2 = parser2.iterator();
          for (String item : parser1) {
              int index1 = getCanonicalIndex(item, false);
              String item2 = it2.next(); // same length so safe
              int index2 = getCanonicalIndex(item2, false);
              if (types[index1][1] != types[index2][1]) {
                  return false;
              }
          }
          return true;
      }
docs: Used by CLDR tooling; not in ICU4C.
  Note, this will not work correctly with normal skeletons, since fields
  that should be related in the two skeletons being compared - like EEE and
  ccc, or y and U - will not be sorted in the same relative place as each
  other when iterating over both TreeSets being compare, using TreeSet's
  "natural" code point ordering (this could be addressed by initializing
  the TreeSet with a comparator that compares fields first by their index
  from getCanonicalIndex()). However if comparing canonical skeletons from
  getCanonicalSkeletonAllowingDuplicates it will be OK regardless, since
  in these skeletons all fields are normalized to the canonical pattern
  char for those fields - M or L to M, E or c to E, y or U to y, etc. -
  so corresponding fields will sort in the same way for both TreeMaps.
  @deprecated This API is ICU internal only.
  @hide original deprecated declaration
  @hide draft / provisional / internal are hidden on Android