aeron-driver/src/main/java/io/aeron/driver/PublicationImage.java
boolean hasActivityAndNotEndOfStream(final long nowNs)
    {
        boolean isActive = true;

        if (((lastPacketTimestampNs + imageLivenessTimeoutNs) - nowNs < 0) ||
            (isEndOfStream && rebuildPosition.getVolatile() >= hwmPosition.get()))
        {
            isActive = false;
        }

        return isActive;
    }
boolean hasActivityAndNotEndOfStream(final long nowNs)
    {
        boolean isActive = true;

        if (((lastPacketTimestampNs + imageLivenessTimeoutNs) - nowNs < 0) ||
            (isEndOfStream && rebuildPosition.getVolatile() >= hwmPosition.get()))
        {
            isActive = false;
        }

        return isActive;
    }
To be called from the {@link Receiver} to see if a image should be retained.

@param nowNs current time to check against for activity.
@return true if the image should be retained otherwise false.