protected static boolean isDiagnosticsEnabled() {
        throw new UnsupportedOperationException(
                        "Operation [isDiagnosticsEnabled] is not supported in jcl-over-slf4j. See also " + UNSUPPORTED_OPERATION_IN_JCL_OVER_SLF4J);
    }
This method exists to ensure signature compatibility.
jcl-over-slf4j/src/main/java/org/apache/commons/logging/LogFactory.java