docs: int addTableColumns(HsqlArrayList expList, int position, HashSet exclude) {
  
          Table table = getTable();
          int   count = table.getColumnCount();
  
          for (int i = 0; i < count; i++) {
              ColumnSchema column = table.getColumn(i);
              String columnName = columnAliases == null ? column.getName().name
                                                        : (String) columnAliases
                                                            .get(i);
  
              if (exclude != null && exclude.contains(columnName)) {
                  continue;
              }
  
              Expression e = new ExpressionColumn(this, column, i);
  
              expList.add(position++, e);
          }
  
          return position;
      }