code: function(context) {
          var node = this.createElementDefaultNS("Extension");
          
          var bounds = context.maxExtent;
          if(bounds) {
              var maxExtent = this.createElementNS(
                  this.namespaces.ol, "ol:maxExtent"
              );
              this.setAttributes(maxExtent, {
                  minx: bounds.left.toPrecision(18),
                  miny: bounds.bottom.toPrecision(18),
                  maxx: bounds.right.toPrecision(18),
                  maxy: bounds.top.toPrecision(18)
              });
              node.appendChild(maxExtent);
          }
          
          return node;
      }
docs: Method: write_ol_MapExtension