code: def _int_growth(z, **cosmo):
      
  
      zmax = 200
  
      if hasattr(z, "__len__"):
          for zval in z:
              assert(zval < zmax)
      else:
          assert(z < zmax)
  
      y, yerr = scipy.integrate.quad(
          lambda z: (1 + z)/(cosmo['omega_M_0']*(1 + z)**3 +
                             cosmo['omega_lambda_0'])**(1.5),
          z, zmax)
  
      return(y)
docs: Returns integral of the linear growth factor from z=200 to z=z