Added pester test as per review feedback

Author: timayabi2020

src/Groups/v1.0/test/New-MgGroup.Tests.ps1

@@ -25,14 +25,29 @@ Describe 'New-MgGroup' {
     Context 'Create' {
         It 'ShouldCreateNewGroup' {
             $CreateGroups = @()
-            1..100 | ForEach-Object {
+            1..10 | ForEach-Object {
                 $Mock.PushScenario('ShouldCreateNewGroup')
                 $CreateGroups += New-MgGroup -DisplayName "new-mggroup-test" -MailEnabled:$false -MailNickname 'unused' -SecurityEnabled
             }
 
-            $CreateGroups | Should -HaveCount 100
+            $CreateGroups | Should -HaveCount 10
             $CreateGroups[0].DisplayName | Should -Be "new-mggroup-test"
             $CreateGroups[0].MailEnabled | Should -BeFalse
         } 
+
+        It 'ShouldHaveASingleResponseObjectIfRHVIsPassed' {
+            $Mock.PushScenario('ShouldCreateNewGroup')
+            $group = New-MgGroup -DisplayName "new-mggroup-test" -MailEnabled:$false -MailNickname 'unused' -SecurityEnabled -RHV rh
+            $group.Count | Should -HaveCount 1
+        }
+
+        It 'ShouldAssignRetrieveHeadersToRHVIfPassed' {
+            $Mock.PushScenario('ShouldCreateNewGroup')
+            New-MgGroup -DisplayName "new-mggroup-test" -MailEnabled:$false -MailNickname 'unused' -SecurityEnabled -RHV rv
+            $rv.Vary | Should -Be "Accept-Encoding"
+            $rv.'Content-Type' | Should -Be "application/json"
+            
+
+        }
     }
 }