docs: public final GeographyValue getGeographyValue(int columnIndex) {
          validateColumnType(columnIndex, VoltType.GEOGRAPHY);
          int offset = getOffset(columnIndex);
          int len = m_buffer.getInt(offset);
          if (len == VoltTable.NULL_STRING_INDICATOR) {
              m_wasNull = true;
              return null;
          }
  
          m_wasNull = false;
          offset += 4;
          GeographyValue gv = GeographyValue.unflattenFromBuffer(m_buffer, offset);
          return gv;
      }