title: Is there a way to keep two functions in sync?
body: <p>I have two functions <code>A</code> and <code>B</code>.  They do the same thing except one of them does it at a more granular level.  I need to make sure that they are doing the same logic forever, that is, if the functionality of one function changes then the other function should change as well.</p>
  
  <p>The best solution (i think) would be to make a general function and a specific function.  Then have one function call the other.  However, in this case it would require too much code refactoring and for the sake of argument suppose its impossible.</p>
  
  <p>Is there a mechanism that allows me to say, when anything inside this code signature changes make sure you alert the user to look at the other function?</p>
  
  <p><strong>Edit #1 @Charles Wood</strong>: I'm looking for a mechanism to do this detection to the source code (with annotations or something.)  But alternatives that achieve the same goal are good too.</p>