Moves iterator @iter to the start of the line @line_number. If @line_number is negative or larger than the number of lines in the buffer, moves @iter to the start of the last line in the buffer.
line number (counted from 0)
See Implementation
Moves iterator @iter to the start of the line @line_number. If @line_number is negative or larger than the number of lines in the buffer, moves @iter to the start of the last line in the buffer.