class Github::Client::GitData::References

def validate_reference(ref)
  refs = (ref =~ (/^(\/)?refs.*/) ? ref : "refs/#{ref}").gsub(/(\/)+/, '/')
  refs.gsub!(/^\//, '')
  unless VALID_REF_PARAM_VALUES['ref'] =~ refs
    raise ArgumentError, "Provided 'reference' is invalid"
  end
end