code: @Deprecated
      public void setElementAt(char index, char value)
      {
          if (isCompact)
              expand();
           values[index] = value;
          touchBlock(index >> BLOCKSHIFT, value);
      }
docs: Set a new value for a Unicode character.
  Set automatically expands the array if it is compacted.
  @param index the character to set the mapped value with
  @param value the new mapped value
  @deprecated This API is ICU internal only.
  @hide draft / provisional / internal are hidden on Android