Gets the buffer at idx, ensuring it is a writable buffer.
You must make sure that idx does not exceed the number of buffers available.
the index
the buffer at idx in group. The returned buffer remains valid as long as list is valid and the buffer is not removed from the list.
1.14
Gets the buffer at idx, ensuring it is a writable buffer.
You must make sure that idx does not exceed the number of buffers available.