on_complete called multiple times

[Sergio-Mira]

We are using PhantomJS and for some reason it is reporting the same result line 3 times, which makes Teaspoon consider that it has results 3 times in a row:
{"type":"result","elapsed":"234.24000","_teaspoon":true}

Unfortunately that means test results are being printed 3 times too and it generates broken JUnit reports as too many closing tags are added.

Is there any possibility that a guard against multiple calls with result could be added to notify_formatters?