docs: @Override
    public boolean getBoolean(int columnIndex) throws SQLException {
      connection.getLogger().log(Level.FINEST, "  getBoolean columnIndex: {0}", columnIndex);
      checkResultSet(columnIndex);
      if (wasNullFlag) {
        return false; // SQL NULL
      }
  
      int col = columnIndex - 1;
      if (Oid.BOOL == fields[col].getOID()) {
        final byte[] v = thisRow[col];
        return (1 == v.length) && (116 == v[0]); // 116 = 't'
      }
  
      if (isBinary(columnIndex)) {
        return BooleanTypeUtil.castToBoolean(readDoubleValue(thisRow[col], fields[col].getOID(), "boolean"));
      }
  
      return BooleanTypeUtil.castToBoolean(getString(columnIndex));
    }