Add TemperatureDelta times SpecificEntropy equals SpecificEnergy (#355)

Author: Ferit Tunçer

UnitsNet.Tests/CustomCode/TemperatureDeltaTests.cs

@@ -38,7 +38,8 @@
 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 // THE SOFTWARE.
-
+using System;
+using Xunit;
 
 namespace UnitsNet.Tests.CustomCode
 {
@@ -61,5 +62,12 @@ public class TemperatureDeltaTests : TemperatureDeltaTestsBase
         protected override double DegreesReaumurInOneKelvin => 0.8;
         protected override double DegreesRoemerInOneKelvin => 21 / 40d;
         protected override double KelvinsInOneKelvin => 1;
+
+        [Fact]
+        public void TemperatureDeltaTimesSpecificEntropyEqualsSpecificEnergy()
+        {
+            SpecificEnergy specificEnergy =  SpecificEntropy.FromJoulesPerKilogramKelvin(10) * TemperatureDelta.FromKelvins(6);
+            Assert.Equal(specificEnergy, SpecificEnergy.FromJoulesPerKilogram(60));
+        }
     }
 }

UnitsNet/CustomCode/Quantities/TemperatureDelta.extra.cs

@@ -38,6 +38,16 @@ public partial struct TemperatureDelta
         {
             return LapseRate.FromDegreesCelciusPerKilometer(left.DegreesCelsiusDelta / right.Kilometers);
         }
+
+        public static SpecificEnergy operator *(SpecificEntropy specificEntropy, TemperatureDelta temperatureDelta)
+        {
+            return SpecificEnergy.FromJoulesPerKilogram(specificEntropy.JoulesPerKilogramKelvin * temperatureDelta.Kelvins);
+        }
+
+        public static SpecificEnergy operator *(TemperatureDelta temperatureDelta, SpecificEntropy specificEntropy)
+        {
+            return specificEntropy * temperatureDelta;
+        }
 #endif
     }
 }