Expose deprecated FormulaEngine and FormulaEngine3Phase types

Signed-off-by: Sahas Subramanian <[email protected]>

Author: shsms

src/frequenz/sdk/timeseries/formula_engine/__init__.py

@@ -0,0 +1,38 @@
+# License: MIT
+# Copyright © 2025 Frequenz Energy-as-a-Service GmbH
+
+"""Deprecated Formula Engine."""
+
+
+from typing_extensions import deprecated
+
+from .._base_types import QuantityT
+from ..formulas._formula import Formula
+from ..formulas._formula_3_phase import Formula3Phase
+
+
+@deprecated(
+    "The FormulaEngine class is deprecated and will be removed in a future release. "
+    + "Please use the Formula class instead."
+)
+class FormulaEngine(Formula[QuantityT]):
+    """Deprecated Formula Engine class.
+
+    This class is deprecated and will be removed in a future release.
+    Please use the `Formula` and `Formula3Phase` classes directly.
+    """
+
+
+@deprecated(
+    "The FormulaEngine3Phase class is deprecated and will be removed in a future release. "
+    + "Please use the Formula3Phase class instead."
+)
+class FormulaEngine3Phase(Formula3Phase[QuantityT]):
+    """Deprecated FormulaEngine3Phase class.
+
+    This class is deprecated and will be removed in a future release.
+    Please use the `Formula3Phase` class directly.
+    """
+
+
+__all__ = ["FormulaEngine", "FormulaEngine3Phase"]