void push_front(float, int, string); //abundance, otu, groupname
void insert(float, int, string); //abundance, otu, groupname
void push_back(float, string); //abundance, groupname
void push_front(float, int, string); //abundance, otu, groupname
void insert(float, int, string); //abundance, otu, groupname
void push_back(float, string); //abundance, groupname