29                       shell=None,  argument
43     if shell is None:
44         dut.shell.InvokeTerminal("check_hal_preconditions")
45         shell = dut.shell.check_hal_preconditions
65             cmd_results = shell.Execute("ps -A")
80                 if not target_file_utils.Exists(path_prefix, shell):
91             shell, hal, bitness, run_as_compliance_test)
97 def CheckFeaturePrecondition(test_instance, dut, shell=None):  argument
123         if shell is None:
124             dut.shell.InvokeTerminal("check_feature_precondition")
125             shell = dut.shell.check_feature_precondition
127         cmd_results = shell.Execute("LD_LIBRARY_PATH= pm list features")
178 def CheckSysPropPrecondition(test_instance, dut, shell=None):  argument
203     if shell is None:
204         dut.shell.InvokeTerminal("check_sysprop_precondition")
205         shell = dut.shell.check_sysprop_precondition
208     cmd_results = shell.Execute('getprop %s' % sysprop_key)