| bag | A bag contains attributes and their values as strings. |
| cc | The context in which the values are retrieved. |
| converterFunc | A function to convert a string value to type T. |
| defaultValue | The value to return if the attribute is not found in the bag. |
| value | If the attribute could be retrieved, the retrieved value converted by the conversion function or the default value if the retrieved value could not de converted. |
bool True if the value is found, false otherwise.
Tries to get the attribute value from the attribute bag.