code: function(property, value) {
          for (var i in this._nodes) {
              if (this._nodes.hasOwnProperty(i)) {
                  var n = this._nodes[i];
                  if ((property in n && n[property] == value) || (n.data && value == n.data[property])) {
                      return n;
                  }
              }
          }
  
          return null;
      }
docs: Returns a node that has a matching property and value in the data
  object that was passed into its constructor.
  @method getNodeByProperty
  @param {object} property the property to search (usually a string)
  @param {object} value the value we want to find (usuall an int or string)
  @return {Node} the matching node, null if no match