fixed syntax error
Merge pull request #20 from felixwiemuth/master

Correction in code box for all languages
Closes #22. Lost rows when handling an unordered join with a RowHandler
Removed @Ignore.
Added a test case for a corner case.
fixes #24. Moving the parse operation to the constructor. Big thanks to Eduardo.
New fix for #22. Better throw an exception to ensure the user knows what
is doing and enables it explicitly.
Minor refactor on tests
ParameterExpressionParser refactored