message: (docs) - fix typo
  Add missing `,` to returned object
diff: @@ -22,7 +22,7 @@ const myGraphCache = cacheExchange({
  addTodo: (variables, cache, info) => {
  console.log(variables); // { id: '1', text: 'optimistic' }
  return {
  - ...variables
  + ...variables,
  __typename: 'Todo', // We still have to let the cache know what entity we are on.
  };
  },
  