code: public int getValue(int ch, boolean [] inBlockZero) 
      {
          // valid, uncompacted trie and valid c?
          if (m_isCompacted_ || ch > UCharacter.MAX_VALUE || ch < 0) {
              if (inBlockZero != null) {
                  inBlockZero[0] = true;
              }
              return 0;
          }
      
          int block = m_index_[ch >> SHIFT_];
          if (inBlockZero != null) {
              inBlockZero[0] = (block == 0);
          }
          return m_data_[Math.abs(block) + (ch & MASK_)];
      }
docs: Get a 32 bit data from the table data
  @param ch  code point for which data is to be retrieved.
  @param inBlockZero  Output parameter, inBlockZero[0] returns true if the
  char maps into block zero, otherwise false.
  @return the 32 bit data value.