whole_func_string: function(filename) {
        return new Promise((resolve, reject) => {
          fs.stat(filename, function(err, stats) {
            if (err && err.code != "ENOENT") {
              reject(err); 
            } else {
              resolve(err ? null : stats);
            }
          });
        });
      }
func_code_string: function(filename) {
        return new Promise((resolve, reject) => {
          fs.stat(filename, function(err, stats) {
            if (err && err.code != "ENOENT") {
              reject(err); 
            } else {
              resolve(err ? null : stats);
            }
          });
        });
      }
func_documentation_string: Returns the stats for a file, or null if the file does not exist
  
  @param filename
  @returns {fs.Stat}
  @async