<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def option(value, is_default=False, label=None):
 """ Annotates a possible value for IValueOptions, will be validated at instance creation time. @param value: a possible value for the IValueOptions being defined. @type value: Any @param is_default: if the option should be the default value. @type is_default: bool @param label: option label or None; if none the string representation of the value will be used as label. @type label: str or unicode or None """

    _annotate("option", value, is_default=is_default, label=label)