Fix merge mistake

Author: gbrgr

crates/iceberg/src/arrow/record_batch_transformer.rs

@@ -218,8 +218,11 @@ impl RecordBatchTransformerBuilder {
         self
     }
 
-    /// Add a virtual field to be included in the output.
-    /// Virtual fields are Arrow fields that are produced by the Parquet reader (e.g., _pos for row position).
+    /// Add a virtual field for a specific field ID.
+    /// This is used for virtual/metadata fields like _pos that are produced by the Parquet reader.
+    ///
+    /// # Arguments
+    /// * `field` - The Arrow field representing the virtual column
     pub(crate) fn with_virtual_field(mut self, field: FieldRef) -> Result<Self> {
         // Extract field ID from metadata
         let field_id = field

crates/iceberg/src/scan/mod.rs

@@ -147,6 +147,12 @@ impl<'a> TableScanBuilder<'a> {
         self
     }
 
+    /// Set the concurrency limit for reading manifest files.
+    pub fn with_manifest_file_concurrency_limit(mut self, limit: usize) -> Self {
+        self.concurrency_limit_manifest_files = limit;
+        self
+    }
+
     /// Sets the manifest entry concurrency limit for this scan
     pub fn with_manifest_entry_concurrency_limit(mut self, limit: usize) -> Self {
         self.concurrency_limit_manifest_entries = limit;