#98420 verifies that the election scheduler is not running when a cluster is stable, but this assertion does not hold in the `AtomicRegisterCoordinatorTests` suite. This issue tracks the work to investigate and fix up the problem.
test/framework/src/main/java/org/elasticsearch/cluster/coordination/AbstractCoordinatorTestCase.java
import org.elasticsearch.client.internal.node.NodeClient;
import org.elasticsearch.cluster.ClusterModule;
import org.elasticsearch.cluster.ClusterState;
import org.elasticsearch.cluster.ClusterStateTaskListener;
import org.elasticsearch.cluster.ClusterStateUpdateTask;
import org.elasticsearch.cluster.ESAllocationTestCase;
import org.elasticsearch.cluster.NodeConnectionsService;
import org.elasticsearch.cluster.TestShardRoutingRoleStrategies;
import org.elasticsearch.cluster.coordination.AbstractCoordinatorTestCase.Cluster.ClusterNode;
import org.elasticsearch.cluster.coordination.CoordinationMetadata.VotingConfiguration;
import org.elasticsearch.cluster.coordination.LinearizabilityChecker.History;
import org.elasticsearch.cluster.coordination.LinearizabilityChecker.SequentialSpec;
import org.elasticsearch.cluster.metadata.Metadata;
import org.elasticsearch.cluster.node.DiscoveryNode;
import org.elasticsearch.cluster.node.DiscoveryNodeRole;
import org.elasticsearch.cluster.node.DiscoveryNodeUtils;
import org.elasticsearch.cluster.routing.BatchedRerouteService;
import org.elasticsearch.cluster.routing.allocation.AllocationService;
import org.elasticsearch.cluster.service.ClusterApplierService;
import org.elasticsearch.cluster.service.ClusterService;
import org.elasticsearch.cluster.service.FakeThreadPoolMasterService;
import org.elasticsearch.common.Randomness;
import org.elasticsearch.common.Strings;
import org.elasticsearch.common.UUIDs;
import org.elasticsearch.common.io.stream.BytesStreamOutput;
import org.elasticsearch.common.io.stream.NamedWriteableAwareStreamInput;
import org.elasticsearch.common.io.stream.NamedWriteableRegistry;
import org.elasticsearch.common.io.stream.RecyclerBytesStreamOutput;
import org.elasticsearch.common.io.stream.StreamInput;
import org.elasticsearch.common.recycler.Recycler;