code: def check_config(self, config):
          
          validation = ""
          required = ["name", "currency", "IBAN", "BIC"]
  
          for config_item in required:
              if config_item not in config:
                  validation += config_item.upper() + "_MISSING "
  
          if not validation:
              return True
          else:
              raise Exception("Config file did not validate. " + validation)
docs: Check the config file for required fields and validity.
          @param config: The config dict.
          @return: True if valid, error string if invalid paramaters where
          encountered.