docs: @JsonProperty("stack_trace")
  	public String getStackTraceString() {
  		if (_stackTrace != null)
  			return _stackTrace;
  
  		StackTraceElement[] ste = getStackTrace();
  		StringBuilder builder = new StringBuilder();
  		if (ste != null) {
  			for (int i = 0; i < ste.length; i++) {
  				if (builder.length() > 0)
  					builder.append(" ");
  				builder.append(ste[i].toString());
  			}
  		}
  		return builder.toString();
  	}