Function graph

graph<NodeDatum, LinkDatum>(): MutGraph<NodeDatum, LinkDatum>
create a new mutable empty MutGraph

When creating a new mutable graph via typescript, you must specify the type of the node data and link data you intend on using, since these types are invariant for mutable graphs.
Type Parameters
- NodeDatum
  the extra user data attached to each node
- LinkDatum
  the extra data attached to each link
Returns MutGraph<NodeDatum, LinkDatum>
Example
Creating a graph with node and link data:
```
// create a new graph
const grf = graph<string, number>();
// add two nodes with some data
const a = grf.node("a");
const b = grf.node("b");
// add a new link with the data `1`
const link = grf.link(a, b, 1);
grf.connected(); // true
```
Example
If undefined extends the data types then they can be omitted:
```
// create a new graph
const grf = graph<undefined | string, undefined | number>();
const a = grf.node();
const b = grf.node();
const link = grf.link(a, b);
grf.connected(); // true
```
- Defined in graph/index.ts:1323