  public TimestampSpec(
      @JsonProperty("column") String timestampColumn,
      @JsonProperty("format") String format
  )
  {
    this.timestampColumn = timestampColumn.toLowerCase();
    this.timestampFormat = format == null ? defaultFormat : format;
    this.timestampConverter = ParserUtils.createTimestampParser(timestampFormat);
  }

  public TimestampSpec(
      @JsonProperty("column") String timestampColumn,
      @JsonProperty("format") String format
  )
  {
    this.timestampColumn = timestampColumn.toLowerCase();
    this.timestampFormat = format == null ? defaultFormat : format.toLowerCase();
    this.timestampConverter = ParserUtils.createTimestampParser(timestampFormat);
  }
