Refer to variables by varname instead of (vname, index)

tests/components/test_dynamic_user_cuts.py

@@ -10,6 +10,7 @@ import networkx as nx
 import pytest
 from gurobipy import GRB
 from networkx import Graph
+from overrides import overrides
 
 from miplearn.components.dynamic_user_cuts import UserCutsComponent
 from miplearn.instance.base import Instance
@@ -24,6 +25,7 @@ class GurobiStableSetProblem(Instance):
         super().__init__()
         self.graph: Graph = graph
 
+    @overrides
     def to_model(self) -> Any:
         model = gp.Model()
         x = [model.addVar(vtype=GRB.BINARY) for _ in range(len(self.graph.nodes))]
@@ -32,9 +34,11 @@ class GurobiStableSetProblem(Instance):
             model.addConstr(x[e[0]] + x[e[1]] <= 1)
         return model
 
+    @overrides
     def has_user_cuts(self) -> bool:
         return True
 
+    @overrides
     def find_violated_user_cuts(self, model):
         assert isinstance(model, gp.Model)
         vals = model.cbGetNodeRel(model.getVars())
@@ -44,6 +48,7 @@ class GurobiStableSetProblem(Instance):
                 violations += [frozenset(clique)]
         return violations
 
+    @overrides
     def build_user_cut(self, model: Any, cid: Hashable) -> Any:
         assert isinstance(cid, FrozenSet)
         x = model.getVars()