iterator.go
func (it *Iterator) ValidForPrefix(prefix []byte) bool {
	return it.Valid() && bytes.HasPrefix(it.item.key, prefix)
}
func (it *Iterator) ValidForPrefix(prefix []byte) bool {
	return it.Valid() && bytes.HasPrefix(it.item.key, prefix)
}
func ( it * Iterator ) ValidForPrefix ( prefix [ ] byte ) bool { return it . Valid ( ) && bytes . HasPrefix ( it . item . key , prefix ) }
// ValidForPrefix returns false when iteration is done
// or when the current key is not prefixed by the specified prefix.
ValidForPrefix returns false when iteration is done or when the current key is not prefixed by the specified prefix .