    # File lib/chef/file_access_control/unix.rb, line 86
          def gid_from_resource(resource)
            return nil if resource == nil or resource.group.nil?
            if resource.group.kind_of?(String)
              diminished_radix_complement( Etc.getgrnam(resource.group).gid )
            elsif resource.group.kind_of?(Integer)
              resource.group
            else
              Chef::Log.error("The `group` parameter of the #@resource resource is set to an invalid value (#{resource.owner.inspect})")
              raise ArgumentError, "cannot resolve #{resource.group.inspect} to gid, group must be a string or integer"
            end
          rescue ArgumentError
            provider.requirements.assert(:create, :create_if_missing, :touch) do |a|
              a.assertion { false }
              a.failure_message(Chef::Exceptions::GroupIDNotFound, "cannot determine group id for '#{resource.group}', does the group exist on this system?")
              a.whyrun("Assuming group #{resource.group} would have been created")
            end
            return nil
          end