/**
 * A linkPart connects two force layout nodes.
 * It reprents a link which can be used in d3's force layout.
 * @param _domain
 * @param _range
 * @param _link
 */
module.exports = function ( _domain, _range, _link ){
  var linkPart = {},
    domain = _domain,
    link = _link,
    range = _range;
  
  // Define d3 properties
  Object.defineProperties(linkPart, {
    "source": { value: domain, writable: true },
    "target": { value: range, writable: true }
  });
  
  
  linkPart.domain = function (){
    return domain;
  };
  
  linkPart.link = function (){
    return link;
  };
  
  linkPart.range = function (){
    return range;
  };
  
  
  return linkPart;
};