SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 2)
    Identifier x
    Identifier y
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier merge_one_two
   Function arrayExists (children 1)
    ExpressionList (children 2)
     Function lambda (children 1)
      ExpressionList (children 2)
       Function tuple (children 1)
        ExpressionList (children 1)
         Identifier _
       Function in (children 1)
        ExpressionList (children 2)
         Identifier _
         Literal UInt64_4294967299
     Identifier x
