SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 1)
    Function count (children 1)
     ExpressionList (children 1)
      Asterisk
   TablesInSelectQuery (children 2)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      Subquery (alias bb) (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 1)
          ExpressionList (children 2)
           Literal Array_[\'a\', \'b\'] (alias a1)
           Literal Array_[UInt64_1] (alias a2)
    TablesInSelectQueryElement (children 1)
     ArrayJoin (children 1)
      ExpressionList (children 2)
       Identifier a1
       Identifier a2
   Set
