(self,t)
if _get_position_at() is not overwritten in a subclass, this function will use euler scheme
if _get_position_at() is not overwritten in a subclass, this function will use euler scheme
if _get_position_at () is not overwritten in a subclass this function will use euler scheme
def generate_position_at(self,t):
        "if _get_position_at() is not overwritten in a subclass, this function will use euler scheme"
        self._check_time(t)        
        if self.startTime<t:
            return self._generate_position_at(t)
def generate_position_at ( self , t ) : self . _check_time ( t ) if self . startTime < t : return self . _generate_position_at ( t )