SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 4)
   ExpressionList (children 5)
    Function grouping (children 1)
     ExpressionList (children 1)
      Identifier key_a
    Function grouping (children 1)
     ExpressionList (children 1)
      Identifier key_b
    Identifier key_a
    Identifier key_b
    Function count (children 1)
     ExpressionList
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      Subquery (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 2)
          ExpressionList (children 2)
           Literal \'value\' (alias key_a)
           Identifier number (alias key_b)
          TablesInSelectQuery (children 1)
           TablesInSelectQueryElement (children 1)
            TableExpression (children 1)
             Function numbers (children 1)
              ExpressionList (children 1)
               Literal UInt64_4
   ExpressionList (children 2)
    ExpressionList (children 1)
     Identifier key_b
    ExpressionList (children 2)
     Identifier key_a
     Identifier key_b
   ExpressionList (children 1)
    OrderByElement (children 1)
     Function tuple (children 1)
      ExpressionList (children 4)
       Function grouping (children 1)
        ExpressionList (children 1)
         Identifier key_a
       Function grouping (children 1)
        ExpressionList (children 1)
         Identifier key_b
       Identifier key_a
       Identifier key_b
