code: def set_final_value(self, description_type, value):
          
          types, _, _, vbox_values, extra_config = self.get_description()
  
          # find offset to description type
          for offset, t in enumerate(types):
              if t == description_type:
                  break
          else:
              raise Exception("Failed to find type for %s" % description_type)
  
          enabled = [True] * len(types)
          vbox_values = list(vbox_values)
          extra_config = list(extra_config)
  
          if isinstance(value, basestring):
              final_value = value
          elif isinstance(value, Enum):
              final_value = str(value._value)
          elif isinstance(value, int):
              final_value = str(value)
          else:
              raise ValueError("Incorrect value type.")
  
          vbox_values[offset] = final_value
          self.set_final_values(enabled, vbox_values, extra_config)
docs: Set the value for the given description type.
  
          in description_type type :class:`VirtualSystemDescriptionType`
  
          in value type str