value = default for default being a list creates a reference not a deep copy
appending to value will have an effect on default
thus default was no longer valid to be appended
fix this by special handling assigning default to value when the default is a list.
value = default for default being a list creates a reference not a deep copy appending to value will have an effect on default thus default was no longer valid to be appended
fix this by special handling assigning default to value when the default is a list.