code: function readFile(file) {
  
      if (file && fs.existsSync(file)) {
          return fs.readFileSync(file);
      }
  
      return null;
  }
docs: Checks if a file exists and if it does returns it's contents.
  Otherwise returns null.
  
  @param {String} file The path to a file.
  
  @returns {String|null} The contents of the file if it exists.