API: Add missing @return Javadoc to fluent/namespace method

api/src/main/java/org/apache/iceberg/ManageSnapshots.java

@@ -66,6 +66,7 @@ public interface ManageSnapshots extends PendingUpdate<Snapshot> {
    *
    * @param snapshotId long id of snapshot id to roll back table to. Must be an ancestor of the
    *     current snapshot
+   * @return this for method chaining
    * @throws IllegalArgumentException If the table has no snapshot with the given id
    * @throws ValidationException If given snapshot id is not an ancestor of the current state
    */
@@ -130,6 +131,7 @@ default ManageSnapshots createBranch(String name) {
    *
    * @param name name of branch to rename
    * @param newName the desired new name of the branch
+   * @return this for method chaining
    * @throws IllegalArgumentException if the branch to rename does not exist or if there is already
    *     a branch with the same name as the desired new name.
    */

api/src/main/java/org/apache/iceberg/SnapshotUpdate.java

@@ -80,6 +80,7 @@ default ThisT writeManifestsWith(ExecutorService executorService, int parallelis
    * Perform operations on a particular branch
    *
    * @param branch which is name of SnapshotRef of type branch.
+   * @return this for method chaining
    */
   default ThisT toBranch(String branch) {
     throw new UnsupportedOperationException(

api/src/main/java/org/apache/iceberg/catalog/SessionCatalog.java

@@ -363,6 +363,7 @@ default List<Namespace> listNamespaces(SessionContext context) {
    * @param namespace a {@link Namespace namespace}
    * @param updates properties to set for the namespace
    * @param removals properties to remove from the namespace
+   * @return true if the namespace metadata was successfully updated, false otherwise
    * @throws NoSuchNamespaceException If the namespace does not exist (optional)
    * @throws UnsupportedOperationException If namespace properties are not supported
    */

api/src/main/java/org/apache/iceberg/catalog/SupportsNamespaces.java

@@ -129,6 +129,7 @@ default List<Namespace> listNamespaces() {
    *
    * @param namespace a namespace. {@link Namespace}
    * @param properties a collection of metadata to apply to the namespace
+   * @return true if the properties were successfully set, false otherwise
    * @throws NoSuchNamespaceException If the namespace does not exist (optional)
    * @throws UnsupportedOperationException If namespace properties are not supported
    */
@@ -142,6 +143,7 @@ boolean setProperties(Namespace namespace, Map<String, String> properties)
    *
    * @param namespace a namespace. {@link Namespace}
    * @param properties a collection of metadata to apply to the namespace
+   * @return true if the properties were successfully removed, false otherwise
    * @throws NoSuchNamespaceException If the namespace does not exist (optional)
    * @throws UnsupportedOperationException If namespace properties are not supported
    */