@Override
        public void remove() {
            if (!mEntryValid) {
                throw new IllegalStateException();
            }
            colRemoveAt(mIndex);
            mIndex--;
            mEnd--;
            mEntryValid = false;
        }
Helper for writing standard Java collection interfaces to a data
structure like {@link ArrayMap}.
android/android_framework/base/src/main/java/github/tornaco/android/thanos/core/util/collection/MapCollections.java