class Berkshelf::Lockfile::Graph

def to_lock
  out = "#{Lockfile::GRAPH}\n"
  @graph.sort.each do |name, item|
    out << "  #{name} (#{item.version})\n"
    unless item.dependencies.empty?
      item.dependencies.sort.each do |dep_name, constraint|
        out << "    #{dep_name} (#{constraint})\n"
      end
    end
  end
  out
end