public boolean markSupported() {
        return canSeekBackwards();
    }
Returns <code>true</code> if marking is supported.
Marking is automatically supported for <code>SeekableStream</code>
subclasses that support seeking backeards.  Subclasses that do
not support seeking backwards but do support marking must override
this method.
plugins/svg-plugin/batik-codec-fix/src/main/java/org/apache/batik/ext/awt/image/codec/util/SeekableStream.java