class Bundler::Graph

def _groups
  relations = Hash.new {|h, k| h[k] = Set.new}
  @env.current_dependencies.each do |dependency|
    dependency.groups.each do |group|
      relations[group.to_s].add(dependency)
      @relations[group.to_s].add(dependency.name)
      @node_options[group.to_s] ||= _make_label(group, :node)
      @edge_options["#{group}_#{dependency.name}"] = _make_label(dependency, :edge)
    end
  end
  @groups = relations.keys
  relations
end