chore: import upstream snapshot with attribution

haystack/testing/sample_components/add_value.py

@@ -0,0 +1,24 @@
+# SPDX-FileCopyrightText: 2022-present deepset GmbH <info@deepset.ai>
+#
+# SPDX-License-Identifier: Apache-2.0
+
+from haystack.core.component import component
+
+
+@component
+class AddFixedValue:
+    """
+    Adds two values together.
+    """
+
+    def __init__(self, add: int = 1) -> None:
+        self.add = add
+
+    @component.output_types(result=int)
+    def run(self, value: int, add: int | None = None):
+        """
+        Adds two values together.
+        """
+        if add is None:
+            add = self.add
+        return {"result": value + add}