class Gem::Dependency

def match?(obj, version=nil, allow_prerelease=false)
  if !version
    name = obj.name
    version = obj.version
  else
    name = obj
  end
  return false unless self.name === name
  version = Gem::Version.new version
  return true if requirement.none? && !version.prerelease?
  return false if version.prerelease? &&
                  !allow_prerelease &&
                  !prerelease?
  requirement.satisfied_by? version
end