class BTree {
public:
BTree (const std::string &filename, unsigned int block_size, int t_t = TYPE_IDENTIFICACION, int k_t = KEY_FIXED, bool create_new_file = false);
class BTree {
public:
BTree (const std::string &filename, unsigned int block_size, int t_t = TYPE_IDENTIFICACION, int k_t = KEY_FIXED, bool create_new_file = false);