code: function _contextPrev() {
  
          // Get the previous node from the sequence
          if (!this._contextState.prevSequence) {
              return undefined;
          }
          if (!this._context.reverse) {
              this._contextState.prevSequence = this._contextState.prevSequence.getPrevious();
              if (!this._contextState.prevSequence) {
                  return undefined;
              }
          }
          var renderNode = this._contextState.prevSequence.get();
          if (!renderNode) {
              this._contextState.prevSequence = undefined;
              return undefined;
          }
          var prevSequence = this._contextState.prevSequence;
          if (this._context.reverse) {
              this._contextState.prevSequence = this._contextState.prevSequence.getPrevious();
          }
          if (this._contextState.lastRenderNode === renderNode) {
            throw 'ViewSequence is corrupted, should never contain the same renderNode twice, index: ' + prevSequence.getIndex();
          }
          this._contextState.lastRenderNode = renderNode;
          return {
              renderNode: renderNode,
              viewSequence: prevSequence,
              prev: true,
              index: --this._contextState.prevGetIndex
          };
      }
docs: Get the previous render-node