if (rev != null || timestamp != null) {
            msg += " (";
            msg += (rev != null ? rev : "");
            if (timestamp != null && !timestamp.isEmpty()) {
                String ts = formatTimestamp(Long.parseLong(timestamp));
                msg += (rev != null ? "; " : "") + ts;
            }
            msg += ")";
        }
        return msg;
    }

import org.slf4j.ILoggerFactory;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import static org.apache.maven.cli.CLIReportingUtils.formatDuration;
import static org.apache.maven.cli.CLIReportingUtils.formatTimestamp;

/**
 * Logs execution events to logger, eventually user-supplied.
 *
 */
public class ExecutionEventLogger extends AbstractExecutionListener {
    private static final int MAX_LOG_PREFIX_SIZE = 8; // "[ERROR] "