AutocompletePrediction.fromJson throws NoSuchMethodError: The method 'map' was called on null.

[stx]

Rare error seen on iOS production app when calling place.autocomplete.get(...):

NoSuchMethodError: NoSuchMethodError: The method 'map' was called on null.
Receiver: null
Tried calling: map<MainTextMatchedSubstring>(Closure: (dynamic) => MainTextMatchedSubstring)
  File "object_patch.dart", line 38, in Object.noSuchMethod
  File "object_patch.dart", line 85, in _objectNoSuchMethod
  File "structured_formatting.dart", line 22, in new StructuredFormatting.fromJson
  File "autocomplete_prediction.dart", line 65, in new AutocompletePrediction.fromJson
  File "autocomplete_response.dart", line 18, in new AutocompleteResponse.fromJson.<fn>
  File "iterable.dart", line 413, in MappedListIterable.elementAt
  File "iterable.dart", line 342, in ListIterator.moveNext
  File "growable_array.dart", line 206, in new _GrowableList._ofEfficientLengthIterable
  File "growable_array.dart", line 153, in new _GrowableList.of
  File "array_patch.dart", line 51, in new List.of
  File "set.dart", line 118, in SetMixin.toList
  File "autocomplete_response.dart", line 19, in new AutocompleteResponse.fromJson
  File "autocomplete_response.dart", line 26, in AutocompleteResponse.parseAutocompleteResult
  File "autocomplete.dart", line 110, in Autocomplete.get

[mbevin]

I see the same error.