class Gem::RequestSet

def tsort_each_child(node)
  node.spec.dependencies.each do |dep|
    next if dep.type == :development
    match = @requests.find { |r| dep.match? r.spec.name, r.spec.version }
    if match
      begin
        yield match
      rescue TSort::Cyclic
      end
    else
      raise Gem::DependencyError, "Unresolved depedency found during sorting - #{dep}"
    end
  end
end