SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 1)
    Function age (children 1)
     ExpressionList (children 3)
      Literal \'second\'
      Function toDateTime64 (children 1)
       ExpressionList (children 3)
        Literal \'1969-12-31 23:59:50.003\'
        Literal UInt64_3
        Literal \'UTC\'
      Function toDateTime64 (children 1)
       ExpressionList (children 3)
        Literal \'1969-12-31 23:59:55.002\'
        Literal UInt64_3
        Literal \'UTC\'
