new_contents: #!/usr/bin/env python
  from math import sqrt, cos, pi, sin
  
  from .trajectory import Trajectory
  
  
  class LemniscateTrajectory(object, Trajectory):
      def __init__(self, radius, period):
          Trajectory.__init__(self)
          self.radius = radius
          self. period = period
  
      def get_position_at(self, t):
          super(LemniscateTrajectory, self).get_position_at(t)
          self.position.x = 2 * sqrt(2) * cos(2 * pi* t / self.period) / (sin(2 * pi * t / self.period) ** 2 + 1)
          self.position.y = 2 * sqrt(2) * sin(2 * pi* t / self.period) * cos(2 * pi* t / self.period) / (sin(2 * pi * t / self.period) ** 2 + 1)
  
          return self.position
  
subject: Implement Lemniscate of Bernoulli trajectory