text: const { createLogger, format, transports } = require('../');
  
  // Ignore log messages if the have { private: true }
  const isSecret = /super secret/;
  const filterSecret = format((info, opts) => {
    info.message = info.message.replace(isSecret, 'su*** se****');
    return info;
  });
  
  const logger = createLogger({
    format: format.combine(
      filterSecret(),
      format.json()
    ),
    transports: [new transports.Console()]
  });
  
  // Outputs: {"level":"error","message":"Public error to share"}
  logger.log({
    level: 'error',
    message: 'Public error to share'
  });
  
  // Outputs: {"level":"error","message":"This is su*** se**** - hide it."}
  logger.log({
    level: 'error',
    message: 'This is super secret - hide it.'
  });
  