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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def output_iface(gandi, iface, datacenters, vms, output_keys, justify=10):
 """ Helper to output an iface information."""

    output_generic(gandi, iface, output_keys, justify)

    if 'vm' in output_keys:
        vm_name = vms.get(iface['vm_id'], {}).get('hostname')
        if vm_name:
            output_line(gandi, 'vm', vm_name, justify)

    if 'dc' in output_keys:
        for dc in datacenters:
            if dc['id'] == iface.get('datacenter_id',
                                     iface.get('datacenter', {}).get('id')):
                dc_name = dc.get('dc_code', dc.get('iso', ''))
                break

        output_line(gandi, 'datacenter', dc_name, justify)

    if 'vlan_' in output_keys:
        vlan = iface.get('vlan') or {}
        output_line(gandi, 'vlan', vlan.get('name', '-'), justify)