https://github.com/tomchentw/react-google-maps/issues/774 also pay attention to this https://cdn.rawgit.com/googlemaps/v3-utility-library/master/markerwithlabel/src/markerwithlabel.js MarkerLabel_.prototype.onRemove it defer from the one that used in this library
tomchentw/react-google-maps#774
also pay attention to this
https://cdn.rawgit.com/googlemaps/v3-utility-library/master/markerwithlabel/src/markerwithlabel.js
MarkerLabel_.prototype.onRemove
it defer from the one that used in this library