code: function can_mangle(name) {
          if (unmangleable.indexOf(name) >= 0) return false;
          if (reserved.indexOf(name) >= 0) return false;
          if (options.only_cache) {
              return cache.props.has(name);
          }
          if (/^-?[0-9]+(\.[0-9]+)?(e[+-][0-9]+)?$/.test(name)) return false;
          return true;
      }
docs: only function declarations after this line