If `left_pad()` calls `send_env_vars()`, how can you add exfiltration to `send_env_vars()` without having to change `left_pad()` to expose the use of the networ

If `left_pad()` calls `send_env_vars()`, how can you add exfiltration to `send_env_vars()` without having to change `left_pad()` to expose the use of the network? "You can't" should be the ONLY acceptable answer.