func (b *boundaryReader) isTerminator(buf []byte) bool {
	idx := bytes.Index(buf, b.final)
	return idx != -1
}
func (b *boundaryReader) isTerminator(buf []byte) bool {
	idx := bytes.Index(buf, b.final)
	return idx != -1
}
func ( b * boundaryReader ) isTerminator ( buf [ ] byte ) bool { idx := bytes . Index ( buf , b . final ) return idx != - 1 }
// isTerminator returns true for --BOUNDARY--
isTerminator returns true for -- BOUNDARY --