Test Studio plugin for Visual Studio version 2015.3.1314.0. 

Steps to reproduce: 

1.Create a simple test in the Visual Studio Plugin and add simple local data with three columns. Rename them to one, two, three respectively. Save and close the test. 

2. Open it again and check the local data tab. 

Expected behavior: To have three columns named one, two, three respectively. 

Actual behavior: There are 5 columns visible one, two, three and two, three once more. If any of the duplicated is deleted, both the duplicate and the original columns disappear. If any of the columns is renamed then the duplicates disappear but only until the next start of the test.