class Gem::Requirement

def none?
  # note that it might be tempting to replace with with RubyGems 2.0's
  # improved implementation. Don't. It requires `DefaultRequirement` to be
  # defined, and more importantantly, these overrides are not used when the
  # running RubyGems defines these methods
  to_s == ">= 0"
end unless allocate.respond_to?(:none?)