new_contents: import datetime
  import re
  import time
  import unittest
  
  from smartbot import utils
  
  
  class Plugin:
      def on_command(self, bot, msg, stdin, stdout, reply):
          if len(msg["args"]) >= 2:
              cmd = msg["args"][1]
              if cmd == "in" or cmd == "at":
                  try:
                      date = utils.datetime.parse(" ".join(msg["args"][1:]))
                  except ValueError:
                      raise Exception("I don't understand that date.")
                  else:
                      duration = max(0, (date - datetime.datetime.now()).total_seconds())
                      time.sleep(duration)
          else:
              print(self.on_help(), file=stdout)
  
      def on_help(self):
          return "Usage: wait in <time>|at <time>"
  
subject: Implement initial wait plugin