message: Guard resultCache access in cacheExchange
diff: @@ -132,9 +132,11 @@ export const afterMutation = (
  });
  pendingOperations.forEach(key => {
  - const operation = (resultCache.get(key) as OperationResult).operation; // Result is guaranteed
  + if (resultCache.has(key)) {
  + const operation = (resultCache.get(key) as OperationResult).operation;
  resultCache.delete(key);
  reexecuteOperation(client, operation);
  + }
  });
  };
  