Allow enabling experimental devices from environment variable (#1194)

kasa/experimental/__init__.py

@@ -1 +1,28 @@
 """Package for experimental."""
+
+from __future__ import annotations
+
+import os
+
+
+class Experimental:
+    """Class for enabling experimental functionality."""
+
+    _enabled: bool | None = None
+    ENV_VAR = "KASA_EXPERIMENTAL"
+
+    @classmethod
+    def set_enabled(cls, enabled):
+        """Set the enabled value."""
+        cls._enabled = enabled
+
+    @classmethod
+    def enabled(cls):
+        """Get the enabled value."""
+        if cls._enabled is not None:
+            return cls._enabled
+
+        if env_var := os.getenv(cls.ENV_VAR):
+            return env_var.lower() in {"true", "1", "t", "on"}
+
+        return False