SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 2)
    Function arrayPushBack (alias x) (children 1)
     ExpressionList (children 2)
      Identifier b
      Function toDecimal64 (children 1)
       ExpressionList (children 2)
        Literal UInt64_0
        Literal UInt64_2
    Function toTypeName (children 1)
     ExpressionList (children 1)
      Identifier x
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier decimal
