title: MyDate may not respond to setDate
body: <p>I have an object calander as</p>
  
  <pre><code> MyDate * calander = [[MyDate alloc] init];
  </code></pre>
  
  <p>in <code>MyDate</code> I have:</p>
  
  <pre><code>-(void) setDate:(NSDate *) NewDate  {
      self.aDate = NewDate;
  .
  .
  .
  }
  </code></pre>
  
  <p>the statement: <code>[calander setDate:mdr.cDate];</code>  issues a warning "MyDate may not respond to setDate."</p>