Minor spelling corrections in documentation of ClusterState (#23592)

core/src/main/java/org/elasticsearch/cluster/ClusterState.java

@@ -66,24 +66,24 @@ import java.util.Set;
 /**
  * Represents the current state of the cluster.
  * <p>
- * The cluster state object is immutable with an exception of the {@link RoutingNodes} structure, which is
+ * The cluster state object is immutable with the exception of the {@link RoutingNodes} structure, which is
  * built on demand from the {@link RoutingTable}.
  * The cluster state can be updated only on the master node. All updates are performed by on a
  * single thread and controlled by the {@link ClusterService}. After every update the
- * {@link Discovery#publish} method publishes new version of the cluster state to all other nodes in the
+ * {@link Discovery#publish} method publishes a new version of the cluster state to all other nodes in the
  * cluster.  The actual publishing mechanism is delegated to the {@link Discovery#publish} method and depends on
  * the type of discovery. In the Zen Discovery it is handled in the {@link PublishClusterStateAction#publish} method. The
  * publishing mechanism can be overridden by other discovery.
  * <p>
  * The cluster state implements the {@link Diffable} interface in order to support publishing of cluster state
  * differences instead of the entire state on each change. The publishing mechanism should only send differences
- * to a node if this node was present in the previous version of the cluster state. If a node is not present was
- * not present in the previous version of the cluster state, such node is unlikely to have the previous cluster
- * state version and should be sent a complete version. In order to make sure that the differences are applied to
+ * to a node if this node was present in the previous version of the cluster state. If a node was
+ * not present in the previous version of the cluster state, this node is unlikely to have the previous cluster
+ * state version and should be sent a complete version. In order to make sure that the differences are applied to the
  * correct version of the cluster state, each cluster state version update generates {@link #stateUUID} that uniquely
  * identifies this version of the state. This uuid is verified by the {@link ClusterStateDiff#apply} method to
- * makes sure that the correct diffs are applied. If uuids don’t match, the {@link ClusterStateDiff#apply} method
- * throws the {@link IncompatibleClusterStateVersionException}, which should cause the publishing mechanism to send
+ * make sure that the correct diffs are applied. If uuids don’t match, the {@link ClusterStateDiff#apply} method
+ * throws the {@link IncompatibleClusterStateVersionException}, which causes the publishing mechanism to send
  * a full version of the cluster state to the node on which this exception was thrown.
  */
 public class ClusterState implements ToXContent, Diffable<ClusterState> {
@@ -252,8 +252,8 @@ public class ClusterState implements ToXContent, Diffable<ClusterState> {
     }
 
     /**
-     * a cluster state supersedes another state iff they are from the same master and the version this state is higher than the other
-     * state.
+     * a cluster state supersedes another state if they are from the same master and the version of this state is higher than that of the
+     * other state.
      * <p>
      * In essence that means that all the changes from the other cluster state are also reflected by the current one
      */