diff --git a/src/caoscrawler/converters.py b/src/caoscrawler/converters.py
index e3f72b10ce2694853d6bc0644c736f0d621ed881..697bd5e4d66b0babb699b8a5ca0606bb94bd3fd3 100644
--- a/src/caoscrawler/converters.py
+++ b/src/caoscrawler/converters.py
@@ -35,7 +35,7 @@ from .structure_elements import (StructureElement, Directory, File, Dict, JSONFi
                                  DictIntegerElement, DictBooleanElement,
                                  DictFloatElement, DictDictElement,
                                  TextElement, DictTextElement, DictElement, DictListElement)
-from typing import Optional, Union
+from typing import List, Optional, Union
 from abc import abstractmethod
 from string import Template
 import yaml_header_tools
@@ -301,6 +301,11 @@ class Converter(object):
                               records,
                               self.definition["records"])
 
+    def filter_children(self, children_with_strings: List[], expr, groupname, rule):
+        """Filter children according to regexp `expr` and `rule`."""
+
+        pass
+
     @abstractmethod
     def typecheck(self, element: StructureElement):
         pass
@@ -675,7 +680,8 @@ class TableConverter(Converter):
                 # The option can often either be a single value or a list of values.
                 # In the latter case each element of the list will be converted to the defined type.
                 if isinstance(el, list):
-                    option_dict[opt_name] = [opt_conversion(el_el) for el_el in el]
+                    option_dict[opt_name] = [
+                        opt_conversion(el_el) for el_el in el]
                 else:
                     option_dict[opt_name] = opt_conversion(el)
         return option_dict
diff --git a/unittests/test_converters.py b/unittests/test_converters.py
index 7a6987b8b3fae9d747f2440de202df5d10a34cc0..0be8dbe7e5782c9f3889095d085df59246e27c4e 100644
--- a/unittests/test_converters.py
+++ b/unittests/test_converters.py
@@ -272,3 +272,24 @@ def test_variable_replacement():
 
     assert handle_value(["a", "b"], values) == (["a", "b"], "single")
     assert handle_value(["$a", "$b"], values) == (["4", "68"], "single")
+
+
+def test_filter_children_of_directory(converter_registry):
+    """Verify that children (i.e., files) in a directory are filtered or sorted
+    correctly.
+
+    """
+    test_dir = Directory("examples_filter_children", rfp("test_directories", "examples_filter_children"))
+    
+    dc = DirectoryConverter(
+        defnition={
+            "match": "(.*)",
+            "filter": {
+                "expr": "",
+                "group": "date",
+                "filter": "only_max"
+            },
+        name="TestOnlyMaxDirectoryConverter",
+        converter_registry=converter_registry
+        }
+    )