Support multiple versions of the EPP Fee Extension

We want to support multiple versions of the fee extension, to allow new features while maintaining backward compatibility. This CL extends the framework and adds one new version, 0.11 (spec version 7), to the existing version 0.6 (spec version 3). A follow-on CL will add version 0.12 (spec version 8).

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=127849044

java/google/registry/model/domain/fee06/FeeCheckResponseExtensionItemV06.java

@@ -0,0 +1,58 @@
+// Copyright 2016 The Domain Registry Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package google.registry.model.domain.fee06;
+
+import google.registry.model.domain.fee.FeeCheckResponseExtensionItem;
+import google.registry.model.domain.fee.FeeQueryResponseExtensionItemImpl;
+import javax.xml.bind.annotation.XmlType;
+import org.joda.money.CurrencyUnit;
+
+/** The version 0.6 response for a domain check on a single resource. */
+@XmlType(propOrder = {"name", "currency", "command", "period", "fee", "feeClass"})
+public class FeeCheckResponseExtensionItemV06
+    extends FeeQueryResponseExtensionItemImpl implements FeeCheckResponseExtensionItem {
+  /** The name of the domain that was checked, with an attribute indicating if it is premium. */
+  String name;
+  
+  CurrencyUnit currency;
+
+  /** Builder for {@link FeeCheckResponseExtensionItemV06}. */
+  public static class Builder
+      extends FeeQueryResponseExtensionItemImpl.Builder<FeeCheckResponseExtensionItemV06, Builder>
+      implements FeeCheckResponseExtensionItem.Builder {
+    
+    @Override
+    public Builder setDomainNameIfSupported(String name) {
+      getInstance().name = name;
+      return this;
+    }
+    
+    @Override
+    public Builder setCurrencyIfSupported(CurrencyUnit currency) {
+      getInstance().currency = currency;
+      return this;
+    }
+    
+    @Override
+    public Builder setAvailIfSupported(boolean avail) {
+      return this;
+    }
+    
+    @Override
+    public Builder setReasonIfSupported(String reason) {
+      return this;
+    }
+  }
+}