Easy chaining constructor function.js

function coolGraph(opts) {
  // Since d3 doesn't like prototype style...
  var me = {
    foo: makeChainableGetterSetterWithDefault('foo'),
    bar: makeChainableGetterSetterWithDefault('bar')
  };
  // Obviously you could do that in a loop if you have a lot of properties, and
  // that function name is pretty gross, a better name might be `property`.
  
  // Now that the object is set up, this will loop through everything in `opts`, and call the right setter on `me`.
  var key;
  for (key in opts) {
    if (!opts.hasOwnProperty(key)) continue;
    me[key](opts[key]);
  }

  // for d3's chaining.
  return me;
}