Generate hashcode on the java types.

editor/tools/plugins/com.google.dart.server/src/com/google/dart/server/generated/types/RefactoringMethodParameter.java

Index: editor/tools/plugins/com.google.dart.server/src/com/google/dart/server/generated/types/RefactoringMethodParameter.java
diff --git a/editor/tools/plugins/com.google.dart.server/src/com/google/dart/server/generated/types/RefactoringMethodParameter.java b/editor/tools/plugins/com.google.dart.server/src/com/google/dart/server/generated/types/RefactoringMethodParameter.java
index df4a1258f39d509a31b0edf52c2bd9780a2e62c2..fed95b16d887c2390189c41729bba1bb66711f2d 100644
--- a/editor/tools/plugins/com.google.dart.server/src/com/google/dart/server/generated/types/RefactoringMethodParameter.java
+++ b/editor/tools/plugins/com.google.dart.server/src/com/google/dart/server/generated/types/RefactoringMethodParameter.java
@@ -26,6 +26,7 @@ import com.google.gson.JsonArray;
 import com.google.gson.JsonElement;
 import com.google.gson.JsonObject;
 import com.google.gson.JsonPrimitive;
+import org.apache.commons.lang3.builder.HashCodeBuilder;
 import java.util.ArrayList;
 import java.util.Iterator;
 import org.apache.commons.lang3.StringUtils;
@@ -156,6 +157,17 @@ public class RefactoringMethodParameter {
     return type;
   }
 
+  @Override
+  public int hashCode() {
+    HashCodeBuilder builder = new HashCodeBuilder();
+    builder.append(id);
+    builder.append(kind);
+    builder.append(type);
+    builder.append(name);
+    builder.append(parameters);
+    return builder.toHashCode();
+  }
+
   public JsonObject toJson() {
     JsonObject jsonObject = new JsonObject();
     if (id != null) {