bson_append_document()
Synopsis
bool
bson_append_document (bson_t       *bson,
                      const char   *key,
                      int           key_length,
                      const bson_t *value);Description
The bson_append_document() function shall append child to bson using the specified key. The type of the field will be a document.
Returns
true if the operation was applied successfully, otherwise false and bson should be discarded.