Where is the defined constraints for the size of topology object

• When trying to add small topology map to  Next demo, used following construct 

var topo = new nx.graphic.Topology({

                    adaptive: true,

                    ...

•  html element where this object is attached has defined size:
• style="width:100%; height:300px; border: 1px solid black;" 
• , but generated topo container have following attributes:
• class="n-topology n-topology-blue" tabindex="0" style="width: 1906px; height: 500px;"
• so there seems to be constraints regarding size of topology object. Adaptive sizing of height above 500px works well, so problem is seen only on height lower than 500px. 

There is a rule for topology's stage size, the default size is 500 * 500, and if you set the property 'padding' to 0, the min size 300* 300.