code: def read_summary_values(self, _step):
      return self._gpu_stats(self._stats_cmd) if self._stats_cmd else {}
  
imports: import csv
  import io
  import subprocess
  import sys
  from guild import util
  from guild.plugins.summary_util import SummaryPlugin
label_desc: Use image node_id 3 for calling the GPUPlugin obj's underlying member method code with example usage: obj.read_summary_values(_step) and returns: unknown