Let's call a pair of request/response an exchange
Revert 80aa5b8df5fb1ba5355b2b9c75bd5dc3989b02d7, broke the execution of a couple of tests.
Set up missing encoding
Recorder doesn't work when setting a proxy, both http and https, close #1545
Proxy is not properly generated
minor clean up
Minor changes: missing space in error message and better variable name
Refactor Extractor API
Refactor Validator API
Introduce RichExpression