UnmodifiableCollectionsSerializer fail to handle Map type

[zhaohehuhu]

OpenTripPlanner/application/src/main/java/org/opentripplanner/kryo/UnmodifiableCollectionsSerializer.java

Line 110 in 7284086

return new ArrayList<>((Collection) coll);

once the type of col is map, this may lead to the exception of class cast.

Expected behavior

Map can be serializable without any error.

Observed behavior

Exception in thread "main" java.lang.ClassCastException: class java.util.Collections$UnmodifiableMap cannot be cast to class java.util.Collection (java.util.Collections$UnmodifiableMap and java.util.Collection are in module java.base of loader 'bootstrap')

Version of OTP used (exact commit hash or JAR name)

Data sets in use (links to GTFS and OSM PBF files)

Command line used to start OTP

Router config and graph build config JSON

Steps to reproduce the problem

[t2gran]

What version of OTP are you using, and which version of Java ?