text: from __future__ import print_function
  from __future__ import absolute_import
  from __future__ import division
  
  from compas.topology import breadth_first_traverse
  
  
  __all__ = [
      'network_is_connected'
  ]
  
  
  def network_is_connected(network):
      """Verify that the network is connected.
  
      Returns
      -------
      bool
          True, if the network is connected.
          False, otherwise.
  
      Notes
      -----
      A network is connected if for every two vertices a path exists connecting them.
  
      Examples
      --------
      >>> import compas
      >>> from compas.datastructures import Network
      >>> from compas.datastructures import network_is_connected
      >>> network = Network.from_obj(compas.get('lines.obj'))
      >>> network_is_connected(network)
      True
      """
      if network.number_of_nodes() == 0:
          return False
      nodes = breadth_first_traverse(network.adjacency, network.get_any_node())
      return len(nodes) == network.number_of_nodes()
  
  
  # ==============================================================================
  # Main
  # ==============================================================================
  
  if __name__ == "__main__":
  
      import doctest
  
      doctest.testmod(globs=globals())
  