Function that checks that a given object is a `Graph`

and
throws an error if not.

## See also

Other Graph operators:
`%>>%()`

,
`as_graph()`

,
`as_pipeop()`

,
`assert_pipeop()`

,
`chain_graphs()`

,
`greplicate()`

,
`gunion()`

,
`mlr_graphs_greplicate`

Function that checks that a given object is a `Graph`

and
throws an error if not.

Other Graph operators:
`%>>%()`

,
`as_graph()`

,
`as_pipeop()`

,
`assert_pipeop()`

,
`chain_graphs()`

,
`greplicate()`

,
`gunion()`

,
`mlr_graphs_greplicate`