<human>:  converting epoch time with milliseconds to datetime
<bot>: Here is some code to convert epoch time represented as milliseconds `s` to string using format '%Y-%m-%d %H:%M:%S.%f'

datetime.datetime.fromtimestamp(s).strftime('%Y-%m-%d %H:%M:%S.%f')

#Warning: this code generation is experimental. Please inspect the code for any bugs before executing.