code: def encode(strs):
      """Encodes a list of strings to a single string.
      :type strs: List[str]
      :rtype: str
      """
      res = ""
      for string in strs.split():
          res += str(len(string)) + ":" + string
      return res
  
label_desc: Use image node_id 1 for calling a global function with example usage: encode(strs) and returns: res