title: Null check for Request body object
body: <p>Is it possible to do integration test for null check.
  I passed null value. </p>
  
  <pre><code>HttpEntity&lt;Employee&gt; entity = new HttpEntity&lt;Employee&gt;(null, headers);
  restTemplate.exchange(url, httpMethod, entity, String.class);
  </code></pre>
  
  <p>I got the below error.</p>
  
  <blockquote>
    <p>{"timestamp":"2018-10-06T14:33:52.113+0000","status":400,"error":"Bad Request","message":"Required request body is missing:"}</p>
  </blockquote>
  
  <pre><code>@RestController
  public class EmployeeController {
  
      @PostMapping(value = "/employee/save", produces = "application/json")
      public Employee save(@RequestBody Employee employee){
          if(employee==null){
              throw new RuntimeException("Employee is null");
          }
      }
  }
  
  class Employee {
  
  }
  </code></pre>