class Gem::RequestSet::GemDependencyAPI

def gemspec(options = {})
  name              = options.delete(:name) || "{,*}"
  path              = options.delete(:path) || "."
  development_group = options.delete(:development_group) || :development
  spec = find_gemspec name, path
  groups = gem_group spec.name, {}
  self_dep = Gem::Dependency.new spec.name, spec.version
  add_dependencies groups, [self_dep]
  add_dependencies groups, spec.runtime_dependencies
  @dependencies[spec.name] = Gem::Requirement.source_set
  spec.dependencies.each do |dep|
    @dependencies[dep.name] = dep.requirement
  end
  groups << development_group
  add_dependencies groups, spec.development_dependencies
  @vendor_set.add_vendor_gem spec.name, path
  gem_requires spec.name, options
end