protected String getAlreadyFilteredAttributeName() {
        String name = getName();
        if (name == null) {
            name = getClass().getName();
        }
        return name + ALREADY_FILTERED_SUFFIX;
    }
Return name of the request attribute that identifies that a request has already been filtered.
<p/>
The default implementation takes the configured {@link #getName() name} and appends &quot;{@code .FILTERED}&quot;.
If the filter is not fully initialized, it falls back to the implementation's class name.

@return the name of the request attribute that identifies that a request has already been filtered.
@see #getName
@see #ALREADY_FILTERED_SUFFIX
web/src/main/java/org/apache/shiro/web/servlet/OncePerRequestFilter.java