code: public int getContainerId(String streamSegmentName) {
          String primaryStreamSegmentName = StreamSegmentNameUtils.extractPrimaryStreamSegmentName(streamSegmentName);
          if (primaryStreamSegmentName != null) {
              // This is a Transaction. Map it to the parent's Container.
              return mapStreamSegmentNameToContainerId(primaryStreamSegmentName);
          } else {
              // Standalone StreamSegment.
              return mapStreamSegmentNameToContainerId(streamSegmentName);
          }
      }
docs: Determines the name of the container to use for the given StreamSegment.
  This value is dependent on the following factors:
  <ul>
  <li>The StreamSegment Name itself.
  <li>The Number of Containers - getTotalContainerCount()
  <li>The mapping strategy implemented by instances of this interface.
  </ul>
  
  @param streamSegmentName The name of the StreamSegment.
  @return Integer indicating the container id for the given StreamSegment.