Merge remote-tracking branch 'goog/stage-aosp-master' into HEAD am: e3e1107fc6 am: 86f459097d
am: 42099c645e

Change-Id: I86d1835828a119f1cde9c37705801d22a799be89
diff --git a/trappy/utils.py b/trappy/utils.py
index 47ef4ab..a06ff1d 100644
--- a/trappy/utils.py
+++ b/trappy/utils.py
@@ -155,7 +155,7 @@
         data['Time'] = data['Time'][1]
         merged_data.append(data)
 
-    df = pd.concat([pr_df, sec_df], keys=['primary', 'secondary']).sort(columns='__line')
+    df = pd.concat([pr_df, sec_df], keys=['primary', 'secondary']).sort_values(by='__line')
     apply_callback(df, df_fn)
     merged_df = pd.DataFrame.from_dict(merged_data)
     merged_df.set_index('Time', inplace=True)