# File lib/chef/cookbook/metadata.rb, line 481
      def self.validate_json(json_str)
        o = Chef::JSONCompat.from_json(json_str)
        metadata = new()
        VERSION_CONSTRAINTS.each do |method_name, hash_key|
          if constraints = o[hash_key]
           constraints.each do |cb_name, constraints|
             metadata.send(method_name, cb_name, *Array(constraints))
           end
          end
        end
        true
      end