old_contents: """Network switch drivers for the HaaS.
  
  This package provides HaaS drivers for various network switches. The
  functions in the top-level module should not be used; they only exist
  as a place to document the interface shared by all of the drivers.
  
  Port IDs and network IDs should both be strings.  The content of them will be
  driver-specific.
  
  """
  
  
  def apply_networking(net_map):
      """Takes in a dictionary, mapping port IDs to network IDs."""
  
  
  def get_new_network_id():
      """Gets a new network ID, valid for this driver.  Returns 'None' if there
      are no more possible IDs available.
      """
  
  def free_network_id(net_id):
      """Marks a network ID as unused, so that it can be re-used for a new
      network.  Can be a no-op on some drivers.
      """
  
  def init_db():
      """Initializes any database tables and/or objects that the driver needs to
      have to function correctly.
      """
  
new_contents: """Network switch drivers for the HaaS.
  
  This package provides HaaS drivers for various network switches. The
  functions in the top-level module should not be used; they only exist
  as a place to document the interface shared by all of the drivers.
  
  Port IDs and network IDs should both be strings.  The content of them will be
  driver-specific.
  
  """
  
  
  def apply_networking(net_map):
      """Takes in a dictionary, mapping port IDs to network IDs.
  
      For each key-value pair (port, network) in the dictionary, set that port
      to access that network.  If network is None, set it to access nothing.
      """
  
  def get_new_network_id():
      """Gets a new network ID, valid for this driver.  Returns 'None' if there
      are no more possible IDs available.
      """
  
  def free_network_id(net_id):
      """Marks a network ID as unused, so that it can be re-used for a new
      network.  Can be a no-op on some drivers.
      """
  
  def init_db():
      """Initializes any database tables and/or objects that the driver needs to
      have to function correctly.
      """
  
subject: Document purpose of 'apply_networking'