default void pushZBy(double z) {
        for (RedUINode n : getSubTree(n -> true)) {
            n.setZPosition(n.getZPosition() + z);
        }
    }
Offset the Z position of this node and its subtree by the given delta

@param z The amount to offset z position
core/src/main/java/mrtjp/projectred/redui/RedUINode.java