SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 1)
    Function seriesDecomposeSTL (children 1)
     ExpressionList (children 2)
      Identifier ts
      Identifier period
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier tb2
   ExpressionList (children 1)
    OrderByElement (children 1)
     Identifier period