code: public boolean setValue(int ch, int value) 
      {
          // valid, uncompacted trie and valid c? 
          if (m_isCompacted_ || ch > UCharacter.MAX_VALUE || ch < 0) {
              return false;
          }
      
          int block = getDataBlock(ch);
          if (block < 0) {
              return false;
          }
      
          m_data_[block + (ch & MASK_)] = value;
          return true;
      }
docs: Sets a 32 bit data in the table data
  @param ch codepoint which data is to be set
  @param value to set
  @return true if the set is successful, otherwise
  if the table has been compacted return false