Minor: add ExecutionPlan.execute() snippet for sync methods

datafusion/physical-plan/src/lib.rs

@@ -235,7 +235,28 @@ pub trait ExecutionPlan: Debug + DisplayAs + Send + Sync {
         Ok(None)
     }
 
-    /// Begin execution of `partition`, returning a stream of [`RecordBatch`]es.
+    /// Start plan execution for `partition`, returning a [`SendableRecordBatchStream`] of [`RecordBatch`]es.
+    ///
+    /// Often its needed to call [`.await`](https://doc.rust-lang.org/std/keyword.await.html) just after the stream async combinators.
+    /// The snippet below modifies the async stream in sync method, sorting the underlying data with external sorter which returns [`SendableRecordBatchStream`], and can also be used to help output/debug the node execution on batch level.
+    ///             
+    /// ```ignore
+    /// fn sort_stream(input: SendableRecordBatchStream, schema: SchemaRef) -> Result<SendableRecordBatchStream> {
+    ///     Ok(Box::pin(RecordBatchStreamAdapter::new(
+    ///         self.schema(),
+    ///         futures::stream::once(async move {
+    ///             while let Some(batch) = input.next().await {
+    ///             let batch = batch?;
+    ///             // Debug/Output
+    ///             dbg!(&batch);
+    ///             sorter.insert_batch(batch).await?;
+    ///         }
+    ///         sorter.sort()
+    ///     })
+    ///     .try_flatten(),
+    ///     )))
+    /// }
+    /// ```
     fn execute(
         &self,
         partition: usize,