code: public static FixedBucketsHistogram fromBase64(String encodedHistogram)
    {
      byte[] asBytes = StringUtils.decodeBase64(encodedHistogram.getBytes(StandardCharsets.UTF_8));
      return fromBytes(asBytes);
    }
docs: Deserialize a Base64-encoded histogram, used when deserializing from JSON (such as when transferring query results)
  or when ingesting a pre-computed histogram.
  
  @param encodedHistogram Base64-encoded histogram
  @return Deserialized object