code: def _refresh_run_scalars(
      self, run, prefix, cur_digest, last_digest, reader
  ):
      summarized = _summarize_scalars(reader)
      if last_digest:
          self._del_scalars(run.id, prefix)
      self._write_summarized(run.id, prefix, summarized)
      self._write_source_digest(run.id, prefix, cur_digest)
  
imports: import logging
  import os
  import sqlite3
  from guild import run_util
  from guild import tfevent
  from guild import util
  from guild import var
label_desc: Use image node_id 4 for calling the ScalarReader obj's underlying member method code with example usage: obj._refresh_run_scalars(run, prefix, cur_digest, last_digest, reader) without return types