typedef struct surf_HostModel surf_HostModel;
typedef struct surf_NetworkModel surf_NetworkModel;
typedef struct surf_StorageModel surf_StorageModel;
typedef struct surf_Resource surf_Resource;
typedef struct surf_HostModel surf_HostModel;
typedef struct surf_NetworkModel surf_NetworkModel;
typedef struct surf_StorageModel surf_StorageModel;
typedef struct surf_Resource surf_Resource;