private IPlayFabPlugin GetPluginInternal(PluginContract contract, string instanceName)
        {
            var key = new PluginContractKey {
                _pluginContract = contract, _pluginName = instanceName
            };
            IPlayFabPlugin plugin;

            if (!this.plugins.TryGetValue(key, out plugin))
            {
                // Requested plugin is not in the cache, create the default one
                switch (contract)
                {
                case PluginContract.PlayFab_Serializer:
                    plugin = this.CreatePlugin <SimpleJsonInstance>();
                    break;

                case PluginContract.PlayFab_Transport:
                    plugin = this.CreatePlayFabTransportPlugin();
                    break;

                default:
                    throw new ArgumentException("This contract is not supported", "contract");
                }

                this.plugins[key] = plugin;
            }

            return(plugin);
        }
        private void SetPluginInternal(IPlayFabPlugin plugin, PluginContract contract, string instanceName)
        {
            if (plugin == null)
            {
                throw new ArgumentNullException("plugin", "Plugin instance cannot be null");
            }

            var key = new PluginContractKey {
                _pluginContract = contract, _pluginName = instanceName
            };

            this.plugins[key] = plugin;
        }