def __init__(self, func, assigned=True):
        """
        @param func: Function wrapped and queried for constraint logic
        @type  func: callable object
        @param assigned: Whether the function may receive unassigned
                         variables or not
        @type  assigned: bool
        """
        self._func = func
        self._assigned = assigned
def __init__ ( self , func , assigned = True ) : self . _func = func self . _assigned = assigned
@param func: Function wrapped and queried for constraint logic
        @type  func: callable object
        @param assigned: Whether the function may receive unassigned
                         variables or not
        @type  assigned: bool