This Ruby example lists the logical networks.

# Get the reference to the root of the services tree:
system_service = connection.system_service

# Get the reference to the service that manages the
# collection of networks:
nws_service = system_service.networks_service

# Retrieve the list of clusters and for each one
# print its name:
nws = nws_service.list
nws.each do |nw|
  puts nw.name
end

In an environment with only the default management network, the example outputs:

ovirtmgmt

For more information, see http://www.rubydoc.info/gems/ovirt-engine-sdk/OvirtSDK4/NetworksService:list.