code: def get_contents_sig(self):
          
  
          try:
              return self.contentsig
          except AttributeError:
              pass
  
          executor = self.get_executor()
  
          result = self.contentsig = SCons.Util.MD5signature(executor.get_contents())
          return result
docs: A helper method for get_cachedir_bsig.
  
          It computes and returns the signature for this
          node's contents.