code: public void genStats(List<JCStatement> trees, Env<GenContext> env, int crtFlags) {
          if (!genCrt) {
              genStats(trees, env);
              return;
          }
          if (trees.length() == 1) {        // mark one statement with the flags
              genStat(trees.head, env, crtFlags | CRT_STATEMENT);
          } else {
              int startpc = code.curCP();
              genStats(trees, env);
              code.crt.put(trees, crtFlags, startpc, code.curCP());
          }
      }
docs: Derived visitor method: check whether CharacterRangeTable
  should be emitted, if so, put a new entry into CRTable
  and call method to generate bytecode.
  If not, just call method to generate bytecode.
  @see    #genStats(List, Env)
  
  @param  trees    The list of trees to be visited.
  @param  env      The environment to use.
  @param  crtFlags The CharacterRangeTable flags
  indicating type of the entry.