title: Single observer with multiple observable
body: <p>I would like to know what would be the implementation with respect to observer design pattern. Like generally we maintain a list of observers in Observable and from its notify we call the update method of the observers. </p>
  
  <p>Now what would be the design in this case? Should i maintain a list of observable in the observers? But then in the update method how i would know which observable has called the update on this observer.</p>
  
  <p>Please share your idea on this. </p>
  
  <p>Thanks,</p>