public HdfsSystemDescriptor withDatePathFormat(String datePathFormat) {
    this.datePathFormat = Optional.ofNullable(StringUtils.stripToNull(datePathFormat));
    return this;
  }
In an HdfsWriter implementation that performs time-based output bucketing,
the user may configure a date format (suitable for inclusion in a file path)
using <code>SimpleDateFormat</code> formatting that the Bucketer implementation will
use to generate HDFS paths and filenames. The more granular this date format, the more
often a bucketing HdfsWriter will begin a new date-path bucket when creating the next output file.
@param datePathFormat date path format
@return this system descriptor
samza-hdfs/src/main/java/org/apache/samza/system/hdfs/descriptors/HdfsSystemDescriptor.java