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src/com/google/gson/JsonNull.java

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+/*
+ * Copyright (C) 2008 Google Inc.
+ *
+ * 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 com.google.gson;
+
+/**
+ * A class representing a Json {@code null} value.
+ *
+ * @author Inderjeet Singh
+ * @author Joel Leitch
+ * @since 1.2
+ */
+public final class JsonNull extends JsonElement {
+  /**
+   * singleton for JsonNull
+   *
+   * @since 1.8
+   */
+  public static final JsonNull INSTANCE = new JsonNull();
+
+  /**
+   * Creates a new JsonNull object.
+   * Deprecated since Gson version 1.8. Use {@link #INSTANCE} instead
+   */
+  @Deprecated
+  public JsonNull() {
+    // Do nothing
+  }
+
+  /**
+   * All instances of JsonNull have the same hash code since they are indistinguishable
+   */
+  @Override
+  public int hashCode() {
+    return JsonNull.class.hashCode();
+  }
+
+  /**
+   * All instances of JsonNull are the same
+   */
+  @Override
+  public boolean equals(Object other) {
+    return this == other || other instanceof JsonNull;
+  }
+}