[Codacy] Warning issue(s) in CallbackHandler.BusinessLogic/Services/CallbackDomainService.cs

**Codacy ID:** `a2e34827fb9f954ea413ce21093d5fe`

  **File:** `CallbackHandler.BusinessLogic/Services/CallbackDomainService.cs`
  **Line:** 36
  **Rule:** BestPractice (Warning)
  **Commit:** `a47f46049823fa60fc0b515d1b81697a52acc35f`

  **Message:** Complete the task associated to this 'TODO' comment.

    **Code Snippet:**
    ```csharp
            // TODO: Validate the reference data 
    ```
