class_docstr: Visualize the debug information.
code: def tracer(self):
      if not self._node_collection:
          w_msg = "Please set `tracer` to `True` when debug, there is nothing to report."
          engine_log.warning(w_msg)
          return None
      if not self._tracer:
          self._tracer = data_visualizer.DataVisualizer(
              self._nodes, self._node_collection
          )
      return self._tracer
  
imports: import json
  from typing import Union, List, Dict, Any
  from towhee.runtime.time_profiler import TimeProfiler
  from towhee.tools.profilers import PerformanceProfiler
  from towhee.datacollection import DataCollection
  from towhee.utils.lazy_import import LazyImport
  from towhee.utils.log import engine_log
  from towhee.utils.serializer import TritonSerializer, TritonParser
label_desc: Use image node_id 7 for calling the Visualizer obj's underlying member method code with example usage: obj.tracer() and returns: self, None