@Override
    public OrcColumn get(String fieldName) {
      int fieldId =
          requireNonNull(
              nameToIdMappingForTableColumns.get(fieldName),
              () -> format("Id mapping for field %s not found", fieldName));
      return idToColumnMappingForFile.get(fieldId);
    }
Gets the index based dereference chain to get from the readColumnHandle to the
expectedColumnHandle
amoro-format-mixed/amoro-mixed-trino/src/main/java/org/apache/amoro/trino/unkeyed/IcebergPageSourceProvider.java