containsPosition method
Returns true if this DocumentNode contains the given position, or false
if the position doesn't sit within this node, or if the position type doesn't
apply to this DocumentNode.
Implementation
@override
bool containsPosition(Object position) {
if (position is! TextNodePosition) {
return false;
}
if (position.offset < 0 || position.offset > text.length) {
return false;
}
return true;
}