comment unused code

Change-Id: I0e0d2aebd6a6af8f2a035b01daa92efc4e0e04e2
fix most of the code

Change-Id: Iaf62ca80c34403e7308e7085e8cf08a6415a658e
fix test_vm_util.py

Change-Id: I50825d8c5ce0407ccff045bfe6bdb686b32ded9c
fix test_driver_api

Change-Id: Ib9ffd71ab0edc8ac2a495772c9062227a8ea4e0c