old_contents: """Implement experimental API."""
  
  #### THIS API IS EXPERIMENTAL.
  #### Discuss with faucet-dev list before relying on this API.
  #### It is subject to change without notice.
  
  # Copyright (C) 2015 Brad Cowie, Christopher Lorier and Joe Stringer.
  # Copyright (C) 2015 Research and Education Advanced Network New Zealand Ltd.
  # Copyright (C) 2015--2017 The Contributors
  #
  # Licensed under the Apache License, Version 2.0 (the "License");
  # you may not use this file except in compliance with the License.
  # You may obtain a copy of the License at
  #
  #    http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  
  
  class FaucetExperimentalAPI(object):
      """An experimental API for communicating with Faucet.
  
      Contains methods for interacting with a running Faucet controller from
      within a RyuApp. This app should be run together with Faucet in the same
      ryu-manager process.
      """
  
      def __init__(self, *args, **kwargs):
          self.faucet = None
  
      def is_registered(self):
          """Return True if registered and ready to serve API requests."""
          return self.faucet is not None
  
      def _register(self, faucet):
          """Register with FAUCET RyuApp."""
          if self.faucet is None:
              self.faucet = faucet
  
      def reload_config(self):
          """Reload config from config file in FAUCET_CONFIG env variable."""
          if self.faucet is not None:
              self.faucet.reload_config(None)
  
      def get_config(self):
          """Get the current running config of Faucet as a python dictionary."""
          if self.faucet is not None:
              return self.faucet.get_config()
          return None
  
      def get_tables(self, dp_id):
          """Get current FAUCET tables as a dict of table name: table no."""
          if self.faucet is not None:
              return self.faucet.get_tables(dp_id)
          return None
  
      def push_config(self, config):
          """Push supplied config to FAUCET."""
          raise NotImplementedError
  
      def add_port_acl(self, port, acl):
          """Add an ACL to a port."""
          raise NotImplementedError
  
      def add_vlan_acl(self, vlan, acl):
          """Add an ACL to a VLAN."""
          raise NotImplementedError
  
      def delete_port_acl(self, port, acl):
          """Delete an ACL from a port."""
          raise NotImplementedError
  
      def delete_vlan_acl(self, vlan, acl):
          """Delete an ACL from a VLAN."""
          raise NotImplementedError
  
new_contents: """Implement experimental API."""
  
  #### THIS API IS EXPERIMENTAL.
  #### Discuss with faucet-dev list before relying on this API,
  #### review http://www.hyrumslaw.com/.
  #### It is subject to change without notice.
  
  # Copyright (C) 2015 Brad Cowie, Christopher Lorier and Joe Stringer.
  # Copyright (C) 2015 Research and Education Advanced Network New Zealand Ltd.
  # Copyright (C) 2015--2017 The Contributors
  #
  # Licensed under the Apache License, Version 2.0 (the "License");
  # you may not use this file except in compliance with the License.
  # You may obtain a copy of the License at
  #
  #    http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  
  
  class FaucetExperimentalAPI(object):
      """An experimental API for communicating with Faucet.
  
      Contains methods for interacting with a running Faucet controller from
      within a RyuApp. This app should be run together with Faucet in the same
      ryu-manager process.
      """
  
      def __init__(self, *args, **kwargs):
          self.faucet = None
  
      def is_registered(self):
          """Return True if registered and ready to serve API requests."""
          return self.faucet is not None
  
      def _register(self, faucet):
          """Register with FAUCET RyuApp."""
          if self.faucet is None:
              self.faucet = faucet
  
      def reload_config(self):
          """Reload config from config file in FAUCET_CONFIG env variable."""
          if self.faucet is not None:
              self.faucet.reload_config(None)
  
      def get_config(self):
          """Get the current running config of Faucet as a python dictionary."""
          if self.faucet is not None:
              return self.faucet.get_config()
          return None
  
      def get_tables(self, dp_id):
          """Get current FAUCET tables as a dict of table name: table no."""
          if self.faucet is not None:
              return self.faucet.get_tables(dp_id)
          return None
  
      def push_config(self, config):
          """Push supplied config to FAUCET."""
          raise NotImplementedError
  
      def add_port_acl(self, port, acl):
          """Add an ACL to a port."""
          raise NotImplementedError
  
      def add_vlan_acl(self, vlan, acl):
          """Add an ACL to a VLAN."""
          raise NotImplementedError
  
      def delete_port_acl(self, port, acl):
          """Delete an ACL from a port."""
          raise NotImplementedError
  
      def delete_vlan_acl(self, vlan, acl):
          """Delete an ACL from a VLAN."""
          raise NotImplementedError
  
subject: Add ref. to http://www.hyrumslaw.com/.