reparent method
Implementation
void reparent(BufferLine owner, int offset) {
_owner?._anchors.remove(this);
_owner = owner;
_owner?._anchors.add(this);
_offset = offset;
}
void reparent(BufferLine owner, int offset) {
_owner?._anchors.remove(this);
_owner = owner;
_owner?._anchors.add(this);
_offset = offset;
}