code: def list_source_code(self, context: int = 5) -> None:
          
          self._verify_entrypoint_selected()
  
          current_trace_frame = self.trace_tuples[
              self.current_trace_frame_index
          ].trace_frame
  
          filename = os.path.join(self.repository_directory, current_trace_frame.filename)
          file_lines: List[str] = []
  
          try:
              # Use readlines instead of enumerate(file) because mock_open
              # doesn't support __iter__ until python 3.7.1.
              with open(filename, "r") as file:
                  file_lines = file.readlines()
          except FileNotFoundError:
              self.warning(f"Couldn't open {filename}.")
              return
  
          self._output_file_lines(current_trace_frame, file_lines, context)
docs: Show source code around the current trace frame location.
  
          Parameters:
              context: int    number of lines to show above and below trace location
                              (default: 5)