class AWS::EC2::NetworkInterfaceCollection

def groups_options options
  # accept this option a variety of different ways
  groups = options[:security_groups]
  groups ||= options[:security_group_ids]
  groups ||= options[:security_group]
  groups ||= options[:security_group_id]
  if groups
    [groups].flatten.map{|sg| sg.is_a?(SecurityGroup) ? sg.id : sg }
  else
    nil
  end
end