public Builder setGroupSummary(boolean isGroupSummary) {
            mGroupSummary = isGroupSummary;
            return this;
        }
Set this notification to be the group summary for a group of notifications.
Grouped notifications may display in a cluster or stack on devices which
support such rendering. Requires a group key also be set using {@link #setGroup}.

@param isGroupSummary Whether this notification should be a group summary.
@return this object for method chaining
android/android_framework/base/src/main/java/github/tornaco/android/thanos/core/compat/NotificationCompat.java