SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 2)
    Function sum (children 1)
     ExpressionList (children 1)
      Literal UInt64_0
    Literal NULL
   TablesInSelectQuery (children 2)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier t0__fuzz_29
    TablesInSelectQueryElement (children 2)
     TableExpression (children 1)
      TableIdentifier t1__fuzz_4
     TableJoin (children 1)
      ExpressionList (children 1)
       Identifier x
   Literal NULL
