A multipoint link (MPL) is a network element that interconnects multiple endpoints at layer-2. Examples of such elements include switches, hubs, and wireless access points. The collection of points interconnected by an MPL are often referred to as a broadcast domain as layer-3 address resolution is accomplished through broadcast messages.
The example below shows a simple MPL connecting 3 hosts.
A multipoint link is not an explicitly modeled element. It's simply a link that happens to have more than 2 endpoints. In this example instead of explicitly encoding the IP addresses like the hello-world example, we've chosen to use the addressing reticulator that will calculate a set of IP addresses for us.
import mergexp as mx
from mergexp.net import addressing, ipv4
net = mx.Topology('alpha', addressing == ipv4)
nodes = [net.device(name) for name in ['a', 'b', 'c']]
lan = net.connect(nodes)