in gdbclient/graph/detachedgraph.go [205:214]
func (d *DetachedVertex) AddProperty(vp VertexProperty) {
if d.properties == nil {
d.properties = make(map[string][]Property)
}
if props, ok := d.properties[vp.PKey()]; ok {
d.properties[vp.PKey()] = append(props, vp)
} else {
d.properties[vp.PKey()] = []Property{vp}
}
}