Fixing TrueFilter example
minor #100 Fixing TrueFilter example (aik099)

This PR was squashed before being merged into the 2.0-dev branch (closes #100).

Discussion
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Fixing TrueFilter example

In the config file $this doesn't represent Sami instance and will lead to Fatal Error.

The syntax highlighting was also fixed in the example code.

Commits
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042226b Fixing TrueFilter example