explicit VirtualMachine(const std::string& name, Host* physical_host, int core_amount);
explicit VirtualMachine(const std::string& name, Host* physical_host, int core_amount, size_t ramsize);
explicit VirtualMachine(const std::string& name, Host* physical_host, int core_amount);
explicit VirtualMachine(const std::string& name, Host* physical_host, int core_amount, size_t ramsize);