Get the diameter of a graph, which is the largest eccentricity in the graph. The graph eccentricity of a node is its shortest path from the farthest other node in the graph.

## Examples

```
# Create a cycle graph
graph <-
create_graph() %>%
add_cycle(n = 5)
# Determine the graph's maximum
# eccentricity
graph %>%
get_max_eccentricity()
#> [1] 4
# Create a full graph and then
# get the maximum eccentricity
# value for that
create_graph() %>%
add_full_graph(n = 10) %>%
get_max_eccentricity()
#> [1] 1
```