old_contents: """
  Store free parameters of model
  """
  
  
  class Configuration(dict):
      """ Dict with dot-notation access functionality
      """
      def __getattr__(self, attr):
          return self.get(attr)
  
      __setattr__ = dict.__setitem__
      __delattr__ = dict.__delitem__
  
  def setup_configuration(
          gamma=8, r=300, D=2.3e-7,
          eta=0, beta=0.2,
          p=0.002,
          c_min=4, c_max=100,
          t_arp=2, t_rrp=7, t_f=1,
          e_max=0.93,
          dt=0.01, t_max=1000, grid_size=100):
      """ Set model paremeters
      """
      return Configuration({
          'gamma': gamma, 'r': r, 'D': D,
          'eta': eta, 'beta': beta,
          'p': p,
          'c_min': c_min, 'c_max': c_max,
          't_arp': t_arp, 't_rrp': t_rrp, 't_f': t_f,
          'e_max': e_max,
          'dt': dt, 't_max': t_max, 'grid_size': grid_size
      })
  
  
  # setup model config
  global config
  def get_config():
      return config
  
  config = setup_configuration()
  
new_contents: """
  Store free parameters of model
  """
  
  
  class Configuration(dict):
      """ Dict with dot-notation access functionality
      """
      def __getattr__(self, attr):
          return self.get(attr)
  
      __setattr__ = dict.__setitem__
      __delattr__ = dict.__delitem__
  
  def setup_configuration(
          gamma=8, r=300, D=2.3e-7 / 0.006**2,
          eta=0, beta=0.2,
          p=0.002,
          c_min=4, c_max=100,
          t_arp=2, t_rrp=7, t_f=1,
          e_max=0.93,
          dt=0.01, t_max=1000, grid_size=100):
      """ Set model paremeters
      """
      return Configuration({
          'gamma': gamma, 'r': r, 'D': D,
          'eta': eta, 'beta': beta,
          'p': p,
          'c_min': c_min, 'c_max': c_max,
          't_arp': t_arp, 't_rrp': t_rrp, 't_f': t_f,
          'e_max': e_max,
          'dt': dt, 't_max': t_max, 'grid_size': grid_size
      })
  
  
  # setup model config
  global config
  def get_config():
      return config
  
  config = setup_configuration()
  
subject: Fix diffusion rate