old_contents: import json
  import sys
  import dateutils
  import timeutil
  
  
  def append_date_to_map(instring):
      "append something to string"
      dat = json.loads(instring)
      dat.setdefault('transforms',[]).append(timeutil.getStr())
      return json.dumps(dat)
new_contents: import json
  import sys
  import dateutils
  import timeutil
  
  
  def append_date_to_map(instring):
      "append something to string"
      dat = json.loads(instring)
      dat.setdefault('transforms',[]).append(timeutil.getStr())
      dat['hello'] = 'hi'
      return json.dumps(dat)
  
subject: Update timestamp.py