code: public static final FileAttribute<?>[] getDefaultRegularFileAttributes(Map<String, ?> env)
      {
          FileAttribute<?>[] attrs = (FileAttribute<?>[]) env.get(DEFAULT_REGULAR_FILE_ATTRIBUTES);
          if (attrs == null)
          {
              attrs = new FileAttribute<?>[]{
                  PosixFilePermissions.asFileAttribute(PosixFilePermissions.fromString("rw-r--r--")),
                  new FileAttributeImpl(OWNER, new UnixUser("root", 0)),
                  new FileAttributeImpl(GROUP, new UnixGroup("root", 0)),
              };
          }
          return attrs;
      }
docs: Return default attributes for new regular file. Either from env or default
  values.
  @param env
  @return