Its well known fact that python default values initialized only once
at the stage if creation function. So if we call function with parameter
foo=[] as default value and change foo.append("bar") at the next call of
the function default value would be ["bar"]. It will save.
Change-Id: Iba9e55bc2d4dfd811ce7d068b6a9cceae7c000d6
0b1be90970