docs: def sleep(self):
      """
      Sleeps until the interval has passed since the last time this function was
      called. This is a synonym for #__call__(). The first time the function is
      called will return immediately and not block. Therefore, it is important to
      put the call at the beginning of the timed block, like this:
  
      # Example
      ```python
      clock = Clock(fps=50)
      while True:
        clock.sleep()
        # Processing ...
      ```
      """
  
      current = time.time()
      if self.last < 0:
        self.last = current
        return
  
      delta = current - self.last
      if delta < self.seconds:
        time.sleep(self.seconds - delta)
        self.last = time.time()