code: function _contextGet(contextNodeOrId) {
          if (this._nodesById && ((contextNodeOrId instanceof String) || (typeof contextNodeOrId === 'string'))) {
              var renderNode = this._nodesById[contextNodeOrId];
              if (!renderNode) {
                  return undefined;
              }
  
              // Return array
              if (renderNode instanceof Array) {
                  var result = [];
                  for (var i = 0, j = renderNode.length; i < j; i++) {
                      result.push({
                          renderNode: renderNode[i],
                          arrayElement: true
                      });
                  }
                  return result;
              }
  
              // Create context node
              return {
                  renderNode: renderNode,
                  byId: true
              };
          }
          else {
              return contextNodeOrId;
          }
      }
docs: Resolve id into a context-node.