private HostSpec getHost(String hostname, Collection<HostSpec> fromHosts) {
        for (HostSpec host : fromHosts)
            if (host.hostname().equals(hostname))
                return host;
        return null;
    }
Returns the input nodes with any port allocations from the hosts
node-repository/src/main/java/com/yahoo/vespa/hosted/provision/provisioning/Activator.java