SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 1)
    Function groupConcatMerge (alias concatenated_text) (children 1)
     ExpressionList (children 1)
      Identifier text
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier test_serialization
   ExpressionList (children 1)
    Identifier id
