code: def _gen_msg(vevent, label, tail, sep):
          
          rem = ['MSG']
          msg = []
          if label:
              msg.append(label)
  
          if hasattr(vevent, 'summary') and vevent.summary.value:
              msg.append(Remind._rem_clean(vevent.summary.value))
          else:
              msg.append('empty reminder')
  
          if hasattr(vevent, 'location') and vevent.location.value:
              msg.append('at %s' % Remind._rem_clean(vevent.location.value))
  
          has_desc = hasattr(vevent, 'description') and vevent.description.value
  
          if tail or has_desc:
              rem.append('%%"%s%%"' % ' '.join(msg))
          else:
              rem.append(' '.join(msg))
  
          if tail:
              rem.append(tail)
  
          if has_desc:
              rem[-1] += sep + Remind._rem_clean(vevent.description.value)
  
          return ' '.join(rem)
docs: Generate a Remind MSG from the given vevent.
          Opposite of _gen_description()