Function tx_insert_end_child 

#[unsafe(no_mangle)]
pub unsafe extern "C" fn tx_insert_end_child(
    doc: *mut TxDocument,
    parent: TxNodeId,
    child: TxNodeId,
) -> TxError

Inserts child as the last child of parent.

Safety

doc must be a valid, non-null pointer to a TxDocument.