Get the nodes in the graph that are identified as articulation points.

## Examples

```
# Create a random graph using the
# `add_gnm_graph()` function
graph <-
create_graph() %>%
add_gnm_graph(
n = 10,
m = 12,
set_seed = 23) %>%
set_node_attrs(
node_attr = shape,
values = "square")
# Get the articulation points
# in the graph (i.e., those
# nodes that if any were to be
# removed, the graph would
# become disconnected)
graph %>%
get_articulation_points()
#> [1] 2 4
# For the articulation points,
# change the node shape to
# a `circle`
graph <-
graph %>%
select_nodes_by_id(
nodes = get_articulation_points(.)) %>%
set_node_attrs_ws(
node_attr = shape,
value = "circle")
```