'Expands the VLAN to the prefix size in private_ipv4_range_size
The expansion will
not be permitted if the proposed IP space overlaps with an
already deployed VLANs IP space.
:param      vlan: The VLAN to update
:type       vlan: :class:`DimensionDataNetworkDomain`
:return: an instance of `DimensionDataVlan`
:rtype: :class:`DimensionDataVlan`'

def ex_expand_vlan(self, vlan):

    edit_node = ET.Element('expandVlan', {'xmlns': TYPES_URN})
    edit_node.set('id', vlan.id)
    ET.SubElement(edit_node, 'privateIpv4PrefixSize').text = vlan.private_ipv4_range_size
    self.connection.request_with_orgId_api_2('network/expandVlan', method='POST', data=ET.tostring(edit_node)).object
    return vlan
