code: func (c *Source) Record() (interface{}, error) {
  	rec, ok := <-c.records
  	if !ok {
  		return nil, io.EOF
  	}
  	return rec.rec, rec.err
  }
docs: // Record returns a map[string]string representing a single data line of a
  // CSV file. Each key is taken from the header, and each value is parsed from a
  // row - empty fields are skipped.