Add test cassette for multi-attachment property validation

This commit introduces a new test cassette for validating single-reference validators in multi-attachment properties. It ensures the behavior of the feature is accurately captured and tested.

tests/test_properties_multi_attachment.py

@@ -0,0 +1,60 @@
+import os
+from pathlib import Path
+
+from pykechain.enums import PropertyType
+from pykechain.models.stored_file import StoredFile
+from pykechain.models.validators import SingleReferenceValidator
+from tests.classes import TestBetamax
+
+
+class TestMultiAttachmentProperties(TestBetamax):
+    def setUp(self):
+        super().setUp()
+        self.test_files_dir = os.path.dirname(
+            os.path.dirname(os.path.abspath(__file__)).replace("\\", "/")
+        )
+        self.upload_path = os.path.join(
+            self.test_files_dir,
+            "tests",
+            "files",
+            "test_upload_image_to_attachment_property",
+            "test_upload_image.png",
+        )
+
+        self.wheel_model = self.project.model("Wheel")
+        self.bike_model = self.project.model("Bike")
+        self.prop_name = "__Test MAP property"
+        self.prop_model = self.bike_model.add_property(
+            name=self.prop_name,
+            property_type=PropertyType.STOREDFILE_REFERENCES_VALUE,
+            description="description of the property",
+            unit="unit of the property",
+            validators=[SingleReferenceValidator],
+        )
+        self.bike = self.bike_model.instance()
+        self.prop = self.bike.property(name=self.prop_name)
+
+    def tearDown(self):
+        if self.prop_model:
+            self.prop_model.delete()
+        super().tearDown()
+
+    def test_get_multi_attachment_property_single_ref_validators(self):
+        self.prop_model.validators = (SingleReferenceValidator(),)
+        self.prop.refresh()
+        self.assertTrue(self.prop.has_validator(SingleReferenceValidator))
+
+    def test_single_stored_file_references_property_value_gets_replaces(self):
+        self.prop_model.validators = (SingleReferenceValidator(),)
+        self.prop.refresh()
+        self.prop.upload(self.upload_path)
+        self.prop.refresh()
+        self.assertIsInstance(self.prop.value, list)
+        self.assertEqual(len(self.prop.value), 1)
+        self.assertIsInstance(self.prop.value[0], StoredFile)
+
+        # replace
+        self.prop.upload(self.upload_path)
+        self.prop.refresh()
+        self.assertEqual(len(self.prop.value), 1)
+        self.assertIsInstance(self.prop.value[0], StoredFile)