'Return the names of parameters these options depend on -- both data
and other param types.'

def get_dependency_names(self):

    rval = []
    if self.dataset_ref_name:
        rval.append(self.dataset_ref_name)
    for filter in self.filters:
        depend = filter.get_dependency_name()
        if depend:
            rval.append(depend)
    return rval
