new_contents: from REM.chen_2009 import model
  from pysb.integrate import Solver
  import numpy as np
  import matplotlib.pyplot as plt
  
  # Replicate matlab simulation
  
  tspan = np.linspace(0, 9000, 901)
  s = Solver(model, tspan, atol=1e-6, rtol=1e-8)
  s.run()
  
subject: Add preliminary simulation script