+ * then this function returns NULL and sets *status to
+ * NOTMUCH_PRIVATE_STATUS_NO_DOCUMENT_FOUND.
+ *
+ * This function can also fail to due lack of available memory,
+ * returning NULL and optionally setting *status to
+ * NOTMUCH_PRIVATE_STATUS_OUT_OF_MEMORY. Caller can pass NULL
+ * for status if uninterested in distinguishing these two cases.