'Attaches a network interface to a load balancer
:param  load_balancer: The load balancer you wish
to attach the network interface to.
:type:  load_balancer: :class:`ProfitBricksLoadBalancer`
:param  network_interface: The network interface
being attached.
:type:  network_interface: :class:`ProfitBricksNetworkInterface`
:rtype  ``bool``'

def ex_attach_nic_to_load_balancer(self, load_balancer, network_interface):

    action = load_balancer.extra['entities']['balancednics']['href']
    body = {'id': network_interface.id}
    self.connection.request(action=action, headers={'Content-Type': 'application/json'}, data=body, method='POST', with_full_url=True)
    return True
