Register register a new visualisation at the url /name/.
The URL parts after the /name/ are treated as the package name and
make available in the template as .package.
type Node struct {
Id string `json:"id"`
Label string `json:"label,omitempty"`
X float64 `json:"x,omitempty"`
Y float64 `json:"y,omitempty"`
Size float64 `json:"size"`
}