text: from cmarshmallow import fields, Schema
  
  
  # Regression test for https://github.com/marshmallow-code/marshmallow/issues/540
  def test_function_field_using_type_annotation():
      def get_split_words(value: str):
          return value.split(';')
  
      class MySchema(Schema):
          friends = fields.Function(deserialize=get_split_words)
  
      data = {'name': 'Bruce Wayne', 'friends': 'Clark;Alfred;Robin'}
      result = MySchema().load(data)
      assert result.data == {'friends': ['Clark', 'Alfred', 'Robin']}
  