Expression function to retrieve default attribute value

I am migrating part of an old ACE application over to AF Analyses, and need to replicate the functionality to fall back to default values in case any of the input attributes are bad. I have taken the time to set the default value in each attribute template, so if one sets the Data Reference to None, the static attribute will have a correct, default value. But the analysis itself should contain functionality to revert to the default value if a bad input attribute value is detected, and with the current functionality I cannot access the default value. I will have to create child attributes for all input attributes, and put the default values there. This will effectively double the number of attributes in my system, and doesn't seem like a very good implementation. I would suggest you create an analysis expression function DefaultValue('attribute') which allows us to access this as a fallback.