better type-safety

core/src/main/java/hudson/matrix/MatrixConfiguration.java

@@ -56,7 +56,7 @@ import java.util.Map;
  *
  * @author Kohsuke Kawaguchi
  */
-public class MatrixConfiguration extends Project<MatrixConfiguration,MatrixRun> implements SCMedItem, NonBlockingTask, Comparable {
+public class MatrixConfiguration extends Project<MatrixConfiguration,MatrixRun> implements SCMedItem, NonBlockingTask, Comparable<MatrixConfiguration> {
     /**
      * The actual value combination.
      */
@@ -289,20 +289,18 @@ public class MatrixConfiguration extends Project<MatrixConfiguration,MatrixRun>
     public void setLogRotator(LogRotator logRotator) {
         throw new UnsupportedOperationException();
     }
-    
-    public int compareTo(Object object){
-        MatrixConfigurationSorter sorter =  getParent().getSorter();
-        try{
-            if(sorter!=null){
-                return getParent().getSorter().compare(this, (MatrixConfiguration)object);
-                }
-            else{
-                    return getDisplayName().compareTo(((MatrixConfiguration)object).getDisplayName());
-                }
-            }
-            catch(Exception e){
-                throw new IllegalArgumentException(e);
+
+    public int compareTo(MatrixConfiguration that) {
+        MatrixConfigurationSorter sorter = getParent().getSorter();
+        try {
+            if (sorter != null) {
+                return getParent().getSorter().compare(this, that);
+            } else {
+                return getDisplayName().compareTo(((MatrixConfiguration) that).getDisplayName());
             }
+        } catch (Exception e) {
+            throw new IllegalArgumentException(e);
+        }
     }
 
     /**