title: Find out how much RAM is used by Thread
body: <p>I would like to know how to find out how much RAM is consumed by certain Threads. 
  There are in my program about 15 classes, each is running in own Thread.</p>
  
  <p>So how can I discover how much RAM is used by Thread1, Thread2, ... Thread15? Is there any method for this?</p>
  
  <p>Thanks for replies! </p>