code: def purchase_vlan(self, vlan_name, debug=False):
          
          vlan_name = {'VLanName': vlan_name}
          json_scheme = self.gen_def_json_scheme('SetPurchaseVLan', vlan_name)
          json_obj = self.call_method_post(method="SetPurchaseVLan", json_scheme=json_scheme)
          if debug is True:
              self.logger.debug(json_obj)
          if json_obj['Success'] is False:
              raise Exception("Cannot purchase new vlan.")
          vlan = Vlan()
          vlan.name = json_obj['Value']['Name']
          vlan.resource_id = json_obj['Value']['ResourceId']
          vlan.vlan_code = json_obj['Value']['VlanCode']
          return vlan
docs: Purchase a new VLAN.
          :param debug: Log the json response if True
          :param vlan_name: String representing the name of the vlan (virtual switch)
          :return: a Vlan Object representing the vlan created