d3.hierarchy(data[, children])
Constructs a root node from the specified hierarchical data. The specified data must be an object representing the root node. For example:
{
"name": "Eve",
"children": [
{
"name": "Cain"
},
{
"name": "Seth",
"children": [
{
"name": "Enos"
},
{
"name": "Noam"
}
]
},
{
"name": "Abel"
},
{
"name": "Awan",
"children": [
{
"n