Emm/OBM — comment on commit 39cce3a5e36132838b2cb0b5ac9bfa1ef60a8208
File: java/sync/common/src/main/java/org/obm/sync/calendar/Event.java line 550
By mbaechler:

It seems that you don't expect caller to modify the returned collection, you should use an immutableSet here.