title: Why do i get "Exception:" when i receive the exception message in dart?
body: <p>Hi I am new to the dart and flutter framework. </p>
  
  <p>I am throwing error like below from my service class where i am calling the API. </p>
  
  <pre><code>if(res["status"]!=200) throw new Exception("Invalid User");
  </code></pre>
  
  <p>and receiving in presenter class like below and printing</p>
  
  <pre><code>.catchError((Object error){
        print(error);
  
  });
  </code></pre>
  
  <p>I am expecting the result as "Invalid User", but am getting with additional word like "Exception: Invalid User". Can you please explain me why this additional word 'Exception' is coming? and how can i get only the string which i am passing.</p>