public boolean contains(Marker other) {
        if (other == null) {
            throw new IllegalArgumentException("Other cannot be null");
        }

        if (this.equals(other)) {
            return true;
        }

        if (hasReferences()) {
            for (Marker ref : referenceList) {
                if (ref.contains(other)) {
                    return true;
                }
            }
        }
        return false;
    }
A simple implementation of the {@link Marker} interface.

@author Ceki G&uuml;lc&uuml;
@author Joern Huxhorn
slf4j-api/src/main/java/org/slf4j/helpers/BasicMarker.java