code: private int getLength()
      {
          if (m_length_ >= 0) {
              return m_length_;
          }
          int length = m_key_.length;
          for (int index = 0; index < length; index ++) {
              if (m_key_[index] == 0) {
                  length = index;
                  break;
              }
          }
          m_length_ = length;
          return m_length_;
      }
docs: Gets the length of the CollationKey
  @return length of the CollationKey