option_2=ChoiceOption(name="variable1",doc="a first variable",values=("val1","val2"),multi=True,properties=frozenset({"basic","mandatory"}),informations={'type':'choice'})
option_3=ChoiceOption(name="variable2",doc="a second variable",values=("val1","val2"),multi=True,properties=frozenset({"standard"}),informations={'type':'choice'})