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 a2
       Identifier a1
   Set
