Specify a name for a `Property` in a code example.

It is good practice to specify a name for the `testing::Property` matcher's use in diagnostics, and we should do so in our examples.

PiperOrigin-RevId: 496406309
Change-Id: Ibb4d1ba63771b5d6855442b91564027cda8ddaca
diff --git a/docs/gmock_cook_book.md b/docs/gmock_cook_book.md
index 6a795ec..7672457 100644
--- a/docs/gmock_cook_book.md
+++ b/docs/gmock_cook_book.md
@@ -904,7 +904,7 @@
 using ::testing::Property;
 
 inline constexpr auto HasFoo = [](const auto& f) {
-  return Property(&MyClass::foo, Contains(f));
+  return Property("foo", &MyClass::foo, Contains(f));
 };
 ...
   EXPECT_THAT(x, HasFoo("blah"));