it prepares the new architecture change,
everything about multithreading in moved in the searx.search.* packages
previously the call to the "init" function of the engines was done in searx.engines:
* the network was not set (request not sent using the defined proxy)
* it requires to monkey patch the code to avoid HTTP requests during the tests
see searx.search.processors.abstract.EngineProcessor
First the method searx call the get_params method.
If the return value is not None, then the searx call the method search.