whole_func_string: async function optimize(file) {
      check(file);
      
      const name = getName(file);
      
      log('reading file ' + path.basename(name));
      
      const data = await readFile(name, 'utf8');
      return onDataRead(file, data);
  }
func_code_string: async function optimize(file) {
      check(file);
      
      const name = getName(file);
      
      log('reading file ' + path.basename(name));
      
      const data = await readFile(name, 'utf8');
      return onDataRead(file, data);
  }
func_documentation_string: function minificate js,css and html files
  
  @param files     -   js, css or html file path