Method initialize

bolt/exec/Generator.cpp:58–64

}

void Generator::initialize() {
  Operator::initialize();
  if (!allExpr_.empty()) {
    genExprs_ =
        std::make_unique<ExprSet>(std::move(allExpr_), operatorCtx_->execCtx());
  }
}

void Generator::preGen() {
  int32_t channel = 0;