/**
* @anchor modules_anchor
*
* @defgroup simulator Simulator
* The "simulator" module contains:
* - a time management class to hold a time and convert between various time units: ns3::Time
* - a scheduler base class used to implement new simulation event schedulers:
* ns3::Scheduler and ns3::SchedulerFactory
* - a simulator class used to create, schedule and cancel events: ns3::Simulator
*
* @defgroup core Core
* \brief The "core" module contains:
* - a Functor class: ns3::Callback
* - an os-independent interface to get access to the elapsed wall clock time: ns3::SystemWallClockMs
* - a class to register regression tests with the test manager: ns3::Test and ns3::TestManager
* - debugging facilities: \ref logging, \ref assert, \ref error
* - \ref randomvariable
* - a base class for objects which need to support reference counting
* and QueryInterface: ns3::Object and ns3::InterfaceId
* - a set of low-level trace facilities integrated in the ns3::Object system: \ref tracing
* - a ns3::ComponentManager which can be used to manage the creation
* of any object which derives from ns3::Object through an ns3::ClassId
* - a smart-pointer class ns3::Ptr designed to work together with ns3::Object
*
* @defgroup common Common
* The "core" module contains:
* - a packet class to create and manipulate simulation packets:
* ns3::Packet, ns3::Header, and ns3::Trailer. This packet class
* also supports per-packet ns3::Tag which are globs of data
* which can be attached to any packet.
*
* @defgroup node Node
* The "node" module contains:
* - a ns3::Node base class which should be subclassed by any new type of
* network Node.
* - models which abstract the MAC-layer from the IP layer protocols:
* ns3::NetDevice and ns3::Channel.
* - models which abstract the application-layer API: ns3::Application,
* ns3::Socket, ns3::SocketFactory, and, ns3::Udp
*
*
* @defgroup devices Devices
*
* @defgroup internetNode InternetNode
*
* The "internet-node" module contains a set of classes which implement the
* APIs defined in the "node" module:
* - an Ipv4/Udp stack with socket support
* - an ARP module
* - an InternetNode class which is a Node subclass.
*
* @defgroup helper Helpers
*
* @defgroup applications Applications
*
* @defgroup mobility Mobility
*
* @defgroup routing Routing
*
* @defgroup constants Constants
* @brief Constants you can change
*
* @defgroup contrib Contrib
*/