# $comment
This is a graph node type used in Stencila Schema for representing provenance,
reactivity and other graphs.

The wrapper gives every graph node a required graph-local `id` for edge
endpoints and embeds the represented Stencila resource or document node.

# properties.type.$comment
This is a special property analogous to JSON-LD's `@type` keyword.

# properties.id.description
The durable graph-local id used by graph edges to reference this graph node.

# properties.node.description
The embedded Stencila node represented by this graph node.