def merge_config(first, second)
        first_hash = first.instance_variable_get(:@hash).deep_dup
        ActiveFedora::Indexing::Map.new(first_hash.merge(second))
      end
def merge_config(first, second)
        first_hash = first.instance_variable_get(:@hash).deep_dup
        ActiveFedora::Indexing::Map.new(first_hash.merge(second))
      end
This can be replaced by a simple merge once
 https://github.com/samvera/active_fedora/pull/1227
 is available to us
 @param [ActiveFedora::Indexing::Map] first
 @param [Hash] second