code: func (sc *StatementContext) SQLDigest() (normalized, sqlDigest string) {
  	sc.digestMemo.Do(func() {
  		sc.digestMemo.normalized, sc.digestMemo.digest = parser.NormalizeDigest(sc.OriginalSQL)
  	})
  	return sc.digestMemo.normalized, sc.digestMemo.digest
  }
docs: // SQLDigest gets normalized and digest for provided sql.
  // it will cache result after first calling.