Clean up input-datetime (#16000)

homeassistant/helpers/config_validation.py

@@ -60,21 +60,6 @@ def has_at_least_one_key(*keys: str) -> Callable:
     return validate
 
 
-def has_at_least_one_key_value(*items: list) -> Callable:
-    """Validate that at least one (key, value) pair exists."""
-    def validate(obj: Dict) -> Dict:
-        """Test (key,value) exist in dict."""
-        if not isinstance(obj, dict):
-            raise vol.Invalid('expected dictionary')
-
-        for item in obj.items():
-            if item in items:
-                return obj
-        raise vol.Invalid('must contain one of {}.'.format(str(items)))
-
-    return validate
-
-
 def boolean(value: Any) -> bool:
     """Validate and coerce a boolean value."""
     if isinstance(value, str):