class_docstr: A class used for accessing tfdbg v2 DebugEvent data on local filesystem.
  
  This class is a short-term hack, mirroring the EventMultiplexer for the main
  TensorBoard plugins (e.g., scalar, histogram and graphs.) As such, it only
  implements the methods relevant to the Debugger V2 pluggin.
  
  TODO(cais): Integrate it with EventMultiplexer and use the integrated class
  from MultiplexerDataProvider for a single path of accessing debugger and
  non-debugger data.
code: def SourceFileList(self, run):
      runs = self.Runs()
      if run not in runs:
          return None
      return self._reader.source_file_list()
  
imports: import threading
  from tensorboard import errors
label_desc: Use image node_id 17 for calling the DebuggerV2EventMultiplexer obj's underlying member method code with example usage: obj.SourceFileList(run) and returns: self, None