feat(storage): add builder and writer skeleton for open appendable object

src/storage/src/lib.rs

@@ -93,6 +93,10 @@ pub mod builder {
     //! Request builders.
     pub mod storage {
         //! Request builders for [Storage][crate::client::Storage].
+        #[cfg(google_cloud_unstable_storage_bidi)]
+        pub use crate::storage::append_object::builder::OpenAppendableObject;
+        #[cfg(google_cloud_unstable_storage_bidi)]
+        pub use crate::storage::append_object::writer::AppendableObjectWriter;
         pub use crate::storage::client::ClientBuilder;
         pub use crate::storage::open_object::OpenObject;
         pub use crate::storage::read_object::ReadObject;

src/storage/src/model_ext.rs

@@ -320,7 +320,7 @@ pub struct WriteObjectRequest {
 /// Represents the parameters of a request to open a new object for exclusive appends.
 ///
 /// Consumers of the `google-cloud-storage` crate rarely have a need to use this type directly, the most common exception is when mocking of the `Storage` client.
-#[derive(Debug, PartialEq)]
+#[derive(Clone, Debug, PartialEq)]
 #[non_exhaustive]
 pub struct OpenAppendableObjectRequest {
     /// The object attributes and pre-conditions for the open operation.

src/storage/src/storage/append_object.rs

@@ -13,3 +13,6 @@
 // limitations under the License.
 
 //! Appendable object uploads (unstable).
+
+pub(crate) mod builder;
+pub(crate) mod writer;