title: Check if a personProperty exists on PeopleManager
body: <p>I have the following code to retrieve data from users within the AD:</p>
  
  <pre><code>PeopleManager peopleManager = new PeopleManager(clientContext);
  PersonProperties personProperties = peopleManager.GetPropertiesFor(loginName);
  clientContext.Load(personProperties);
  clientContext.Load(personProperties, p =&gt; p.AccountName, p =&gt; p.UserProfileProperties);
  clientContext.ExecuteQuery();
  
  var personalUrl=personProperties.PersonalUrl;
  </code></pre>
  
  <p>That last line throws an error on <em>some</em> but not on all users:</p>
  
  <blockquote>
    <p>Microsoft.SharePoint.Client.ServerObjectNullReferenceException: Object reference not set to an instance of an object on server. The object is associated with method GetPropertiesFor.
       at Microsoft.SharePoint.Client.ClientObject.CheckUninitializedProperty(String propName)
       at Microsoft.SharePoint.Client.UserProfiles.PersonProperties.get_PersonalUrl()</p>
  </blockquote>
  
  <p>So simply spoken: Is there a method to check if that property is set before trying to retrieve the value?</p>
  
  <p>Or is a <code>try..catch</code> the only (ugly) way to solve this?</p>