public static ByteSource bytes(File file) {
            return new SimpleByteSource(file);
        }
Returns a new {@code ByteSource} instance representing the specified File's bytes.

@param file the file to represent as a {@code ByteSource} instance.
@return a new {@code ByteSource} instance representing the specified File's bytes.
lang/src/main/java/org/apache/shiro/lang/util/ByteSource.java