class Gem::TestCase

def dependency_request dep, from_name, from_version, parent = nil
  remote = Gem::Source.new @uri
  unless parent then
    parent_dep = dep from_name, from_version
    parent = Gem::Resolver::DependencyRequest.new parent_dep, nil
  end
  spec = Gem::Resolver::IndexSpecification.new \
    nil, from_name, from_version, remote, Gem::Platform::RUBY
  activation = Gem::Resolver::ActivationRequest.new spec, parent
  Gem::Resolver::DependencyRequest.new dep, activation
end