int feather_edits(int64_t start, int64_t end, int64_t units);
int64_t get_feather(int64_t selectionstart, int64_t selectionend);
int feather_edits(int64_t start, int64_t end, int64_t units);
int64_t get_feather(int64_t selectionstart, int64_t selectionend);