Error dealing with Multipolygons

[ericboucher]

I get the following error TypeError: Cannot assign to read only property 'type' of object '#<Object>'

TypeError: Cannot assign to read only property 'type' of object '#<Object>'
GeoJSONUtils.fixMultiPoly
node_modules/max-inscribed-circle/utils/geojson-utils.js:21
  18 | fixMultiPoly(polygon) {
  19 |     if(polygon.geometry.type === 'MultiPolygon' && polygon.geometry.coordinates[0].length === 1) {
  20 |         // Handle a Polygon in the form of a MultiPolygon
> 21 |         polygon.geometry.type = 'Polygon';
     | ^  22 |         polygon.geometry.coordinates = polygon.geometry.coordinates[0];
  23 | 
  24 |         return polygon;
View compiled
maxInscribedCircle
node_modules/max-inscribed-circle/max-inscribed-circle.js:50
  47 | const numSegments = options.numSegments;
  48 | const units = options.units;
  49 | 
> 50 | polygon = GeoJSONUtils.fixMultiPoly(polygon);
     | ^  51 | const polySites = GeoJSONUtils.sites(polygon, numSegments, decimalPlaces);
  52 | const diagram = voronoi.compute(polySites.sites, polySites.bbox);
  53 | const vertices = {

Here is an example of a failing Multipolygon. I have tried to create a new copy of the object to allow mutations but without any luck.

[PieceMaker]

Do you have a sample GeoJSON MultiPolygon you can provide that throws this error? I looked at the tests and there already exist tests for MultiPolygons, albeit simple ones, that are passing.