7 8 5
this_is_a_test
@__
this_line_gets_deleted
this_line_stays_the_same
this_line_gets_changed
@_
end_of_test

this_is_a_test
@__
this_line_stays_the_same
this_line_gets_changed,_like_so
@_
these_two_lines_are_added
@_
end_of_test

this_is_a_test
@__
this_line_stays_the_same
@_
end_of_test