1 files changed, 9 insertions, 2 deletions

diff --git a/glucometerutils/common.py b/glucometerutils/common.py
index ddb2607..bf944c8 100644
--- a/glucometerutils/common.py
+++ b/glucometerutils/common.py
@@ -6,7 +6,7 @@
 import datetime
 import enum
 import textwrap
-from typing import Any, Dict, Optional, Sequence
+from typing import Any, Dict, Optional, Sequence, Union
 
 import attr
 
@@ -91,6 +91,10 @@ class KetoneReading:
     timestamp: datetime.datetime
     value: float
     comment: str = ""
+    measure_method: MeasurementMethod = attr.ib(
+        default=MeasurementMethod.BLOOD_SAMPLE,
+        validator=attr.validators.in_({MeasurementMethod.BLOOD_SAMPLE}),
+    )
     extra_data: Dict[str, Any] = attr.Factory(dict)
 
     def as_csv(self, unit: Unit) -> str:
@@ -100,7 +104,7 @@ class KetoneReading:
         return '"%s","%.2f","%s","%s"' % (
             self.timestamp,
             self.value,
-            MeasurementMethod.BLOOD_SAMPLE.value,
+            self.measure_method.value,
             self.comment,
         )
 
@@ -123,6 +127,9 @@ class TimeAdjustment:
         )
 
 
+AnyReading = Union[GlucoseReading, KetoneReading, TimeAdjustment]
+
+
 @attr.s(auto_attribs=True)
 class MeterInfo:
     """General information about the meter.