Remove dead _solicitation_window alias module

CHANGELOG.md

@@ -5,6 +5,12 @@ Format: [Keep a Changelog](https://keepachangelog.com/en/1.1.0/)
 
 ## [Unreleased]
 
+### Removed
+- Dead module `philanthropy/preprocessing/_solicitation_window.py`. The
+  deprecated alias `SolicitationWindowTransformer` already resolved only
+  through `__getattr__` in `__init__.py`; the file was unimported and
+  dragged coverage to 0%. Closes #153.
+
 ### Fixed
 - `GratefulPatientFeaturizer` now reports one fallback `general` service line
   per known donor when the encounter table omits the service-line column.

CONTRIBUTORS.md

@@ -76,3 +76,4 @@ too; say so in the PR and it stays out.
 Not sure where to start? See
 [CONTRIBUTING.md](CONTRIBUTING.md) and the
 [good first issues](https://github.com/PhilanthroPy-Project/PhilanthroPy/issues?q=is%3Aissue+is%3Aopen+label%3A%22good+first+issue%22).
+- [@haas26p-ctrl](https://github.com/haas26p-ctrl): deleted the unused `_solicitation_window` alias module ([#153](https://github.com/PhilanthroPy-Project/PhilanthroPy/issues/153)).

philanthropy/preprocessing/__init__.py

@@ -37,8 +37,12 @@
 ]
 
 
+# Deprecated aliases resolve through __getattr__ (PEP 562) to the same class
+# object as the canonical name — not a subclass — so isinstance/clone behave
+# as before. They are removed in 1.0.0. No separate alias modules: those would
+# be unimported dead code (the alias never loads them).
 _DEPRECATED_ALIASES = {
-    # alias -> (canonical name, module attribute)
+    # alias -> canonical attribute name in this module's globals()
     "SolicitationWindowTransformer": "DischargeToSolicitationWindowTransformer",
 }