Read the passage carefully and answer the question given below: What's more exciting than having a fresh hot pizza delivered to your door? How about having it brought to you by a robot ? Thanks to Domino’s Robotic Unit or DRU, that just became a reality! On March 8, the three-foot tall robot delivered its first pizza to some lucky residents in Brisbane, Australia. The fully autonomous DRU is the result of collaboration between Domino's Pizza Australia and Sydney-based startup Marathon Robotics. The 450-pound machine that travels at a maximum speed of 12.4 miles an hour can traverse a distance of up to 12-miles and back, before requiring a battery recharge. LIDAR, a laser-based sensor technology similar to the one used in self-driving cars, enables DRU to detect and avoid obstacles, while traditional sensors, much like those used in vacuum robots ensure its path is safe as it heads to its destination. DRU's weather and waterproof acrylic plastic exterior protects the food from the elements while its aluminum and steel interior ensures that the pies remain piping hot! The robot can fit up to ten pizzas and even has a separate cold area to accommodate drink orders Equipped with both Google Maps and GPS-guidance DRU can navigate bike paths and sidewalks and also find the most efficient way to its destination. Since the robot does not have to contend with road traffic, it could potentially make deliveries a lot quicker than humans. To access their food, customers have to enter the unique code provided to them by the company. This not only ensures that they pick up the right pizza,but also prevents the pies from getting stolen en route. Though Domino's has so far built just a single prototype, they expect additional DRU's to be ready for service in their various Queensland locations within the next six months. But don't expect these super cute robots to replace humans anytime soon. According to Domino's the DRU still needs extensive testing,which the company believes could take up to two years. And then there is also the issue of regulations. The public use of autonomous vehicles is still banned in most countries. But Don Meij, the CEO and Managing Director of Domino’s Pizza Australia New Zealand Ltd, is not worried. He is "confident that one day [DRU] will become an integral part of the Domino’s family.” We for one cannot wait Question: The meaning of the underlined word ‘prototype’ in the fifth paragraph is: