code: public function startNested($name) : Profiler
      {
          $nestedProfiler = new Profiler($name, $this->ticker);
          $nestedProfiler->parent = $this;
          $nestedProfiler->level = $this->level + 1;
          $this->entries[] = $nestedProfiler;
          ProfilerRegistry::instance()->register($name, $nestedProfiler);
          return $this;
      }
docs: Creates a nested profiler, which can be obtained from {@link ProfilerRegistry} by its name.
  
  @param string $name
  @return $this