old_contents: from PLC.Faults import *
  from PLC.Method import Method
  from PLC.Parameter import Parameter, Mixed
  from PLC.NodeGroups import NodeGroup, NodeGroups
  from PLC.Auth import PasswordAuth
  
  class AddNodeGroup(Method):
      """
      Adds a new node group. Any values specified in optional_vals are used,
      otherwise defaults are used.
  
      Returns the new nodegroup_id (> 0) if successful, faults otherwise.
      """
  
      roles = ['admin']
  
      accepts = [
          PasswordAuth(),
          NodeGroup.fields['name'],
          NodeGroup.fields['description']
          ]
  
      returns = Parameter(int, 'New nodegroup_id (> 0) if successful')
  
      def call(self, auth, name, description):
  	# Create node group
          nodegroup = NodeGroup(self.api, {'name': name, 'description': description})
          nodegroup.sync()
  
          return nodegroup['nodegroup_id']
  
new_contents: from PLC.Faults import *
  from PLC.Method import Method
  from PLC.Parameter import Parameter, Mixed
  from PLC.NodeGroups import NodeGroup, NodeGroups
  from PLC.Auth import PasswordAuth
  
  can_update = lambda (field, value): field in \
               ['description']
  
  class AddNodeGroup(Method):
      """
      Adds a new node group. Any values specified in nodegroup_fields
      are used, otherwise defaults are used.
  
      Returns the new nodegroup_id (> 0) if successful, faults otherwise.
      """
  
      roles = ['admin']
  
      update_fields = dict(filter(can_update, NodeGroup.fields.items()))
  
      accepts = [
          PasswordAuth(),
          NodeGroup.fields['name'],
          update_fields
          ]
  
      returns = Parameter(int, 'New nodegroup_id (> 0) if successful')
  
      def call(self, auth, name, nodegroup_fields = {}):
          nodegroup_fields = dict(filter(can_update, nodegroup_fields.items()))
          nodegroup = NodeGroup(self.api, nodegroup_fields)
          nodegroup['name'] = name
          nodegroup.sync()
  
          return nodegroup['nodegroup_id']
  
subject: make description an optional field