sub chains_loc { $_[0]{chains_loc} }
sub set_chains_loc { $_[0]{chains_loc} = $_[1] }
-sub cache { $_[0]{cache} ||= {} }
-sub clear_cache { %{$_[0]->cache} = () }
-
=head2 _dump_file()
This method takes no arguments. It's used to print out a textual representation