+/*
+ * Attempt to populate the "id" and "timestamp" fields of the event header if
+ * they are present, unset and their types are integers.
+ *
+ * Not finding these fields or encountering unexpected types is not an error
+ * since the user may have defined a different event header layout. In this
+ * case, it is expected that the fields be manually populated before appending
+ * an event to a stream.
+ */