title: How to use Morgan logger?
body: <p>I cannot log with Morgan. It doesn't log info to console. The documentation doesn't tell how to use it.</p>
  
  <p>I want to see what a variable is. This is a code from <code>response.js</code> file of expressjs framework:</p>
  
  <pre><code>var logger = require("morgan");
  
  res.render = function(view, options, fn){
    options = options || {};
    var self = this;
    var req = this.req;
    var app = req.app;
  
    // support callback function as second arg
    if ('function' == typeof options) {
      fn = options, options = {};
    }
  
    // merge res.locals
    options._locals = self.locals;
  
    // default callback to respond
    fn = fn || function(err, str){
      if (err) return req.next(err);
      self.send(str);
    };
  
    // Here I want to see what fn is
    // But it doesn't show me anything in console
    // How to use it?
    logger(fn);
  
    // render
    app.render(view, options, fn);
  };
  </code></pre>
  
  <p>How to use Morgan?</p>