float decimal places precision in node

I am trying to dump a node into a file with float values.

```
YAML::Node node;
node["Map"]["FloatValue"] = 123.456;

std::ofstream fout("file.yaml");
fout << node;
```

The output that I get is 
```
Map:
    FloatValue: 123.456001
```

Is there anyway I can set the precision in a node?
