old_contents: 
  import eHive
  
  class TestRunnable(eHive.BaseRunnable):
      """Simple Runnable to test as a standaloneJob"""
  
      def param_defaults(self):
          return {
              'alpha' : 37,
              'beta' : 78
          }
  
      def fetch_input(self):
          self.warning("Fetch the world !")
          print("alpha is", self.param_required('alpha'))
          print("beta is", self.param_required('beta'))
  
      def run(self):
          self.warning("Run the world !")
          s = self.param('alpha') + self.param('beta')
          print("set gamma to", s)
          self.param('gamma', s)
  
      def write_output(self):
          self.warning("Write to the world !")
          print("gamma is", self.param('gamma'))
          self.dataflow( {'gamma': self.param('gamma')}, 2 )
  
  
new_contents: 
  import eHive
  
  class TestRunnable(eHive.BaseRunnable):
      """Simple Runnable to test as a standaloneJob"""
  
      def param_defaults(self):
          return {
              'alpha' : 37,
              'beta' : 78,
              'gamma' : '#alpha#',
              'delta' : 'one#hash',
          }
  
      def fetch_input(self):
          self.warning("Fetch the world !")
          print("alpha is", self.param_required('alpha'))
          print("beta is", self.param_required('beta'))
          print("gamma is", self.param_required('gamma'))
          print("delta is", self.param_required('delta'))
  
      def run(self):
          self.warning("Run the world !")
          s = self.param('alpha') + self.param('beta')
          print("set gamma to", s)
          self.param('gamma', s)
  
      def write_output(self):
          self.warning("Write to the world !")
          print("gamma is", self.param('gamma'))
          self.dataflow( {'gamma': self.param('gamma')}, 2 )
  
  
subject: Add substitution example + one hash, to TestRunnable.py