get_global_setting_value(python_id, attribute, value_type=None, default=None) | python_id: The Python ID of the global setting to retrieve.
attribute: The attribute of the global setting to retrieve. Valid values are class, alpha120, python_id, parameter, description, template_code and invisible.
value_type: Determines the type the return value should be converted into. For example int or str.
default: The value that should be returned if no global setting with the given python_id exists. | The value of the global setting or the default if the setting does not exist. If no default is given and the setting does not exist, a ValueError is raised. | Retrieves a global setting. After retrieving a value once, it will be cached until cache_clear() is called. |