SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 1)
    Identifier x
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier merge_s64_u64
   Function in (children 1)
    ExpressionList (children 2)
     Identifier x
     Literal UInt64_1
