function measureCb(_this, data) {
		return function () {
			if (isObject(data)) {
				data.fillColor = _this.styleStack.getProperty('fillColor');
				data.fillOpacity = _this.styleStack.getProperty('fillOpacity');
			}
			return _this.measureNode(data);
		};
	}
Creates an instance of DocumentContext - a store for current x, y positions and available width/height.
It facilitates column divisions and vertical sync