save the config back to the external source.
save the config back to the external source. Any parameters for this method should have already been extracted from the call to readArgs
as with readArgs, this should in general be implemented as an abstract override with a call to super
Read config from an external source, and use that to modify the set of arguments.
Read config from an external source, and use that to modify the set of arguments. The "original" arguments are given as an argument to this function, so that this method can base its behavior on those arguments. (Eg., it can take a filename from those args.) It should return the complete set of args that should be used. It is free to choose to completely replace the original args, append to them, modify them, etc.
in general, implementations should be abstract override with a call to super, to allow multiple external configs via the Stackable Trait Pattern
a mixin for ExternalConfig to make sure that the parse and setting of fields is done before the ExternalConfig is processed. Mix it in first. A second parsing and the validation will take place after the ExternalConfig is applied.