func NewLimitedBufferReader(r io.Reader, n int) io.Reader {
	return &limitedBufferReader{
		r: r,
		n: n,
	}
}
func NewLimitedBufferReader(r io.Reader, n int) io.Reader {
	return &limitedBufferReader{
		r: r,
		n: n,
	}
}
// NewLimitedBufferReader returns a reader that reads from the given reader
// but limits the amount of data returned to at most n bytes.