An amenable graph, also called an identified graph (Kiefer et al. 2015), is a finite graph 
for which color refinement
distinguishes 
from every nonisomorphic graph 
(Arvind et al. 2017).
Equivalently, 
is amenable iff its Weisfeiler-Leman
dimension is 1, since color refinement is
the one-dimensional Weisfeiler-Leman algorithm.
Arvind et al. (2017) characterized amenable graphs and showed that the class
can be recognized in time 
for a graph with 
vertices and 
edges.
