Add 'removeUnusedLambdaParameters' to the cleanup settings.

Signed-off-by: Roland Grunberg <rgrunber@redhat.com>

Author: rgrunber

document/_java.learnMoreAboutCleanUps.md

@@ -405,4 +405,30 @@ public class A {
         Parser a12;
     }
 }
+```
+
+### `removeUnusedLambdaParameters`
+
+Rename unused lambda parameters, or unused pattern variables to `_`.
+
+For example:
+
+```java
+J j = (a, b) -> System.out.println(a);
+
+switch (r) {
+    case R(_, long l) -> {}
+    case R r2 -> {}
+}
+```
+
+becomes:
+
+```java
+J j = (a, _) -> System.out.println(a);
+
+switch (r) {
+    case R(_, _) -> {}
+    case R _ -> {}
+}
 ```

package.json

@@ -1313,7 +1313,8 @@
                 "switchExpression",
                 "tryWithResource",
                 "renameFileToType",
-                "organizeImports"
+                "organizeImports",
+                "removeUnusedLambdaParameters"
               ]
             },
             "default": [