1. A computerized apparatus comprising: a processor; an interface for obtaining a test template associated with a target computerized system, the test template comprises a plurality of template instructions; a test generator configured to generate a test associated with the test template obtained by said interface, said test generator comprises: a state simulator configured to determine a state of the target computerized system associated with an execution of the test; a template instruction selector configured to select a template instruction from the test template based on the state of the target computerized system determined by said state simulator; an instruction generator configured to generate an instruction based on the state of the target computerized system and the template instruction selected by said template instruction selector.