Traceback (most recent call last):
  File "/opt/representer/bin/run.py", line 56, in <module>
    main()
  File "/opt/representer/bin/run.py", line 52, in main
    representer.represent(args.slug, args.input, args.output)
  File "/opt/representer/representer/__init__.py", line 110, in represent
    out[0:0] = ['## BEGIN NORMALIZED CODE ##', representation.dump_code(), "## END NORMALIZED CODE ##", '']
                                               ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/representer/representer/__init__.py", line 45, in dump_code
    code = utils.to_source(self._tree)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/representer/representer/utils.py", line 107, in to_source
    return ast.unparse(tree)
           ^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/ast.py", line 1708, in unparse
    return unparser.visit(ast_obj)
           ^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/ast.py", line 818, in visit
    self.traverse(node)
  File "/usr/local/lib/python3.11/ast.py", line 809, in traverse
    super().visit(node)
  File "/usr/local/lib/python3.11/ast.py", line 418, in visit
    return visitor(node)
           ^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/ast.py", line 833, in visit_Module
    self._write_docstring_and_traverse_body(node)
  File "/usr/local/lib/python3.11/ast.py", line 826, in _write_docstring_and_traverse_body
    self.traverse(node.body)
  File "/usr/local/lib/python3.11/ast.py", line 807, in traverse
    self.traverse(item)
  File "/usr/local/lib/python3.11/ast.py", line 809, in traverse
    super().visit(node)
  File "/usr/local/lib/python3.11/ast.py", line 418, in visit
    return visitor(node)
           ^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/ast.py", line 1029, in visit_ClassDef
    self._write_docstring_and_traverse_body(node)
  File "/usr/local/lib/python3.11/ast.py", line 826, in _write_docstring_and_traverse_body
    self.traverse(node.body)
  File "/usr/local/lib/python3.11/ast.py", line 807, in traverse
    self.traverse(item)
  File "/usr/local/lib/python3.11/ast.py", line 809, in traverse
    super().visit(node)
  File "/usr/local/lib/python3.11/ast.py", line 418, in visit
    return visitor(node)
           ^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/ast.py", line 875, in visit_Assign
    self.traverse(node.value)
  File "/usr/local/lib/python3.11/ast.py", line 809, in traverse
    super().visit(node)
  File "/usr/local/lib/python3.11/ast.py", line 418, in visit
    return visitor(node)
           ^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/ast.py", line 422, in generic_visit
    for field, value in iter_fields(node):
  File "/usr/local/lib/python3.11/ast.py", line 260, in iter_fields
    for field in node._fields:
                 ^^^^^^^^^^^^
AttributeError: 'NoneType' object has no attribute '_fields'