public SubClass withDefaultStreamOffsetDefault(OffsetType offsetType) {
    this.defaultStreamOffsetDefaultOptional = Optional.ofNullable(offsetType);
    return (SubClass) this;
  }
If a container starts up without a checkpoint, this property determines where in the input stream we should start
consuming. The value must be an {@link OffsetType}, one of the following:
<ul>
 <li>upcoming: Start processing messages that are published after the job starts.
               Any messages published while the job was not running are not processed.
 <li>oldest: Start processing at the oldest available message in the system,
             and reprocess the entire available message history.
</ul>
This property is for all streams obtained using this system descriptor. To set it for an individual stream,
see {@link InputDescriptor#withOffsetDefault}.
If both are defined, the stream-level definition takes precedence.

@param offsetType offset type to start processing from
@return this system descriptor
samza-api/src/main/java/org/apache/samza/system/descriptors/SystemDescriptor.java