public Vendor LocateVendors(decimal latitude, decimal longitude, List<string> keywords)
 {
     var vendor = new Vendor();
     vendor.Name = "Taco Truck";
     vendor.Latitude = latitude;
     vendor.Longitude = longitude;
     return vendor;
 }
 public Vendor LocateVendor(string name)
 {
     var vendor = new Vendor();
     vendor.Name = "Taco Truck Man";
     vendor.Latitude = 10;
     vendor.Longitude = 12;
     return vendor;
 }