Function write_all 

pub fn write_all<'a, W: Write, I: IntoIterator<Item = &'a Record>>(
    writer: &mut W,
    records: I,
) -> Result<()>

Write an iterator of records, one per line.

Any record whose verify_id() returns false is written anyway — this function is a pure serializer, not a validator. Use Record::verify_id before calling if you want to refuse tampered records.