SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 1)
    Function toStartOfInterval (children 1)
     ExpressionList (children 2)
      Identifier a
      Function toIntervalMillisecond (children 1)
       ExpressionList (children 1)
        Literal UInt64_1
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      Subquery (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 1)
          ExpressionList (children 1)
           Function toDateTime64 (alias a) (children 1)
            ExpressionList (children 2)
             Literal \'1980-12-12 12:12:12.123456\'
             Literal UInt64_6