ouroboros.js

/**
 * @class
 * @property {CGPoint} cgPoint
 */
function Node(cgPoint) {
  this.point = cgPoint || { x: 0, y: 0 };
  this.edges = [];
}

/**
 * @param {string} nodeID
 */
Node.prototype.addEdge = function(node) {
  node && this.edges.push(node);
  return this;
};

var st = new Node();

st.addEdge(new Node()); // OK
st.addEdge(st);         // This one crashes Sketch :(