Function remove_child 

pub fn remove_child(
    doc: &mut BaseDocument,
    parent: NodeId,
    child: NodeId,
) -> Result<NodeId>

parent.removeChild(child), returning the child.

Copied behaviour worth knowing: parent is not checked. Upstream removes the child from wherever it actually is rather than raising the DOM’s NotFoundError, and the node is detached rather than dropped so that wrappers stay valid.