code: def read(self):
      self.pos[0] += self.vel[0]
      self.pos[1] += self.vel[1]
  
      return [
          self.pos[0] + randn() * self.noise_std,
          self.pos[1] + randn() * self.noise_std,
      ]
  
imports: from __future__ import absolute_import, division, print_function
  import numpy.random
  from numpy.random import randn
  import numpy
  import matplotlib.pyplot
  from pytest import approx
  from filterpy.kalman import KalmanFilter, update, predict, batch_filter
  from filterpy.common import Q_discrete_white_noise, kinematic_kf, Saver
  from filterpy.stats import mahalanobis
  from scipy.linalg import block_diag, norm
label_desc: Use image node_id 2 for calling the PosSensor1 obj's underlying member method code with example usage: obj.read() and returns: list