code: public String flattenToString() {
      if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled()) SibTr.entry(tc, "flattenToString");
  
      StringBuffer buffer = new StringBuffer();
      byte [] bytes = this.flattenToBytes();
      HexString.binToHex(bytes, 0, bytes.length, buffer);
  
      if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled()) SibTr.exit(tc, "flattenToString");
      return new String(buffer);
    }
docs: Flattens the SIMessageHandle to a String.
  This flattened format can be restored into a SIMessageHandle by using
  com.ibm.wsspi.sib.core.SIMessageHandleRestorer.restoreFromString(String data)
  
  @see com.ibm.wsspi.sib.core.SIMessageHandleRestorer#restoreFromString(String)
  @return String The flattened SIMessageHandle.