Setting minimal distance between diagram nodes?

Hi.
I try to use GoJs, and got some problems.
I try to display nodes and relation with values.

But I got a problem. Diagram nodes displayed to close for each other and user can not see arrow labels.

Here is ilustration of my problem link to image

For displaying diagram data I use js object with nodes and relation array.
for example:

const visualizationObjExample = {
  nodes: [
    {key: "A", color: 'red'},
    {key: "B", color: 'red'},
    {key: "C", color: 'red'},
  ],
  links: [
    { from: "A", to: "B", value: '$12'},
    { from: "B", to: "C", value: '$15'},
  ],
};

For initial configuration I use next code

`const { nodes, links } = this.state;
    const diagram = goObj(go.Diagram, this.refs.goJsDiv, {initialContentAlignment: go.Spot.Center});
    const $ = go.GraphObject.make;

diagram.nodeTemplate =
  $(go.Node, "Auto",
    $(go.Shape, "RoundedRectangle", { strokeWidth: 0 },
      new go.Binding("fill", "color")),
    $(go.TextBlock,
      { margin: 8 },
      new go.Binding("text", "key"))
  );
diagram.linkTemplate =
  $(go.Link,
    $(go.Shape),
    $(go.Shape, { toArrow: "Standard" }),
    $(go.TextBlock,
      new go.Binding("text", "value"))
);

diagram.model = new go.GraphLinksModel(nodes, links);` 

Is it exist way to set the minimal distance between diagram nodes?

Thanks.

Since you are not setting a layout or assigning locations to nodes, your diagram is using the default layout to assign locations. Perhaps you’d like to use one of the automatic layouts described in the layout intro page and set a spacing property. Or maybe you want to bind the location of your nodes and set them yourself in the model, as can be seen in many of our samples, including this one.