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The argument type 'Iterable<Map<String, dynamic>>' can't be assigned to the parameter type 'List<Map<String, dynamic>>'

I have the below function to take List data from API call and populate pop-up metadata with the first 5 instances of key/value pairs.

   var mappedList = boards.boards!.take(5).toList(); 
   // now, from the list above, I map each result into a key-value pair
    var mappedValues = mappedList.map((m) => { 'headsign': m.getString('headsign'), 'time': m.getString('time') });
   // this list will look like:
   // [{ headsign: 'value1', title: 'title1'}, { headsign: 'value2', title: 'value2' }]
   // Now moving mappedValues list to showDialog
   String title = ("Title Test");
   _DropDownList(mappedValues, title);
  Future<void> _DropDownList(List<Map<String, dynamic>> values, String title) async {
         var test1 = ListBody(
I receive the error
    The argument type 'Iterable<Map<String, dynamic>>' can't be assigned to the parameter type 'List<Map<String, dynamic>>'
on the line
     _DropDownList(mappedValues, title); //(on 'mappedValues')
This error links to
   var mappedValues = mappedList.map((m) =>
And the error is with the map section of the function. I have tried casting as etc but can't get it to work or go through as a List<Map<String, dynamic>>
Thanks
Update
If I change to iterable like so I get the error The operator '[]' isn't defined for the type 'Iterable<Map<String, dynamic>>'. on [index] where highlighted below
Future<void> _DropDownList(Iterable<Map<String, dynamic>> values, String title) async {
         var test1 = ListBody(
              children: List.generate(
                values.length, (index) {
   *[index]*                return Text(values[index]['headsign']);
Thanks
                A List is one type of Iterable, but not all Iterables are Lists.  Does your _DropDownList function actually need to take a List argument, or could it take an Iterable instead?  If so, I'd just change _DropDownList's parameter type to be more general.  Otherwise you'll need to create a List from the Iterable by calling .toList() on it.
– jamesdlin
                Mar 3, 2022 at 12:00
You can easily change an Iterable to a list by calling toList() so just change
var mappedValues = mappedList.map((m) => { 'headsign': m.getString('headsign'), 'time': m.getString('time') });
var mappedValues = mappedList.map((m) => { 'headsign': m.getString('headsign'), 'time': m.getString('time') }).toList();
        
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