code: public void genStat(JCTree tree, Env<GenContext> env) {
          if (code.isAlive()) {
              code.statBegin(tree.pos);
              genDef(tree, env);
          } else if (env.info.isSwitch && tree.hasTag(VARDEF)) {
              // variables whose declarations are in a switch
              // can be used even if the decl is unreachable.
              code.newLocal(((JCVariableDecl) tree).sym);
          }
      }
docs: Derived visitor method: generate code for a statement.