private int priorityToLevelInt(Priority p) {
        switch (p.level) {
        case Level.TRACE_INT:
        case Level.X_TRACE_INT:
            return LocationAwareLogger.TRACE_INT;
        case Priority.DEBUG_INT:
            return LocationAwareLogger.DEBUG_INT;
        case Priority.INFO_INT:
            return LocationAwareLogger.INFO_INT;
        case Priority.WARN_INT:
            return LocationAwareLogger.WARN_INT;
        case Priority.ERROR_INT:
            return LocationAwareLogger.ERROR_INT;
        case Priority.FATAL_INT:
            return LocationAwareLogger.ERROR_INT;
        default:
            throw new IllegalStateException("Unknown Priority " + p);
        }
    }
Delegates to {@link org.slf4j.Logger#error(String,Throwable)} method in
SLF4J. In addition, the call is marked with a marker named "FATAL".

@param message a message to log
@param t       a throwable to log
log4j-over-slf4j/src/main/java/org/apache/log4j/Category.java