+ # head_kind and tail_kind columns are now virtual,
+ # equivilent functionality is now provided by
+ # 'is_a', so fix up any old-style 'filter' clauses.
+ @filters = @filters.map do |k|
+ if k[0] == 'head_kind' and k[1] == '='
+ ['head_uuid', 'is_a', k[2]]
+ elsif k[0] == 'tail_kind' and k[1] == '='
+ ['tail_uuid', 'is_a', k[2]]
+ else
+ k
+ end
+ end