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diff --git a/src/main/java/org/apache/commons/lang3/mutable/MutableInt.java b/src/main/java/org/apache/commons/lang3/mutable/MutableInt.java
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+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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 org.apache.commons.lang3.mutable;
+
+import org.apache.commons.lang3.math.NumberUtils;
+
+/**
+ * A mutable {@code int} wrapper.
+ * <p>
+ * Note that as MutableInt does not extend Integer, it is not treated by String.format as an Integer parameter.
+ * </p>
+ *
+ * @see Integer
+ * @since 2.1
+ */
+public class MutableInt extends Number implements Comparable<MutableInt>, Mutable<Number> {
+
+    /**
+     * Required for serialization support.
+     *
+     * @see java.io.Serializable
+     */
+    private static final long serialVersionUID = 512176391864L;
+
+    /** The mutable value. */
+    private int value;
+
+    /**
+     * Constructs a new MutableInt with the default value of zero.
+     */
+    public MutableInt() {
+    }
+
+    /**
+     * Constructs a new MutableInt with the specified value.
+     *
+     * @param value  the initial value to store
+     */
+    public MutableInt(final int value) {
+        this.value = value;
+    }
+
+    /**
+     * Constructs a new MutableInt with the specified value.
+     *
+     * @param value  the initial value to store, not null
+     * @throws NullPointerException if the object is null
+     */
+    public MutableInt(final Number value) {
+        this.value = value.intValue();
+    }
+
+    /**
+     * Constructs a new MutableInt parsing the given string.
+     *
+     * @param value  the string to parse, not null
+     * @throws NumberFormatException if the string cannot be parsed into an int
+     * @since 2.5
+     */
+    public MutableInt(final String value) {
+        this.value = Integer.parseInt(value);
+    }
+
+    /**
+     * Gets the value as a Integer instance.
+     *
+     * @return the value as a Integer, never null
+     */
+    @Override
+    public Integer getValue() {
+        return Integer.valueOf(this.value);
+    }
+
+    /**
+     * Sets the value.
+     *
+     * @param value  the value to set
+     */
+    public void setValue(final int value) {
+        this.value = value;
+    }
+
+    /**
+     * Sets the value from any Number instance.
+     *
+     * @param value  the value to set, not null
+     * @throws NullPointerException if the object is null
+     */
+    @Override
+    public void setValue(final Number value) {
+        this.value = value.intValue();
+    }
+
+    /**
+     * Increments the value.
+     *
+     * @since 2.2
+     */
+    public void increment() {
+        value++;
+    }
+
+    /**
+     * Increments this instance's value by 1; this method returns the value associated with the instance
+     * immediately prior to the increment operation. This method is not thread safe.
+     *
+     * @return the value associated with the instance before it was incremented
+     * @since 3.5
+     */
+    public int getAndIncrement() {
+        final int last = value;
+        value++;
+        return last;
+    }
+
+    /**
+     * Increments this instance's value by 1; this method returns the value associated with the instance
+     * immediately after the increment operation. This method is not thread safe.
+     *
+     * @return the value associated with the instance after it is incremented
+     * @since 3.5
+     */
+    public int incrementAndGet() {
+        value++;
+        return value;
+    }
+
+    /**
+     * Decrements the value.
+     *
+     * @since 2.2
+     */
+    public void decrement() {
+        value--;
+    }
+
+    /**
+     * Decrements this instance's value by 1; this method returns the value associated with the instance
+     * immediately prior to the decrement operation. This method is not thread safe.
+     *
+     * @return the value associated with the instance before it was decremented
+     * @since 3.5
+     */
+    public int getAndDecrement() {
+        final int last = value;
+        value--;
+        return last;
+    }
+
+    /**
+     * Decrements this instance's value by 1; this method returns the value associated with the instance
+     * immediately after the decrement operation. This method is not thread safe.
+     *
+     * @return the value associated with the instance after it is decremented
+     * @since 3.5
+     */
+    public int decrementAndGet() {
+        value--;
+        return value;
+    }
+
+    /**
+     * Adds a value to the value of this instance.
+     *
+     * @param operand  the value to add, not null
+     * @since 2.2
+     */
+    public void add(final int operand) {
+        this.value += operand;
+    }
+
+    /**
+     * Adds a value to the value of this instance.
+     *
+     * @param operand  the value to add, not null
+     * @throws NullPointerException if the object is null
+     * @since 2.2
+     */
+    public void add(final Number operand) {
+        this.value += operand.intValue();
+    }
+
+    /**
+     * Subtracts a value from the value of this instance.
+     *
+     * @param operand  the value to subtract, not null
+     * @since 2.2
+     */
+    public void subtract(final int operand) {
+        this.value -= operand;
+    }
+
+    /**
+     * Subtracts a value from the value of this instance.
+     *
+     * @param operand  the value to subtract, not null
+     * @throws NullPointerException if the object is null
+     * @since 2.2
+     */
+    public void subtract(final Number operand) {
+        this.value -= operand.intValue();
+    }
+
+    /**
+     * Increments this instance's value by {@code operand}; this method returns the value associated with the instance
+     * immediately after the addition operation. This method is not thread safe.
+     *
+     * @param operand the quantity to add, not null
+     * @return the value associated with this instance after adding the operand
+     * @since 3.5
+     */
+    public int addAndGet(final int operand) {
+        this.value += operand;
+        return value;
+    }
+
+    /**
+     * Increments this instance's value by {@code operand}; this method returns the value associated with the instance
+     * immediately after the addition operation. This method is not thread safe.
+     *
+     * @param operand the quantity to add, not null
+     * @throws NullPointerException if {@code operand} is null
+     * @return the value associated with this instance after adding the operand
+     * @since 3.5
+     */
+    public int addAndGet(final Number operand) {
+        this.value += operand.intValue();
+        return value;
+    }
+
+    /**
+     * Increments this instance's value by {@code operand}; this method returns the value associated with the instance
+     * immediately prior to the addition operation. This method is not thread safe.
+     *
+     * @param operand the quantity to add, not null
+     * @return the value associated with this instance immediately before the operand was added
+     * @since 3.5
+     */
+    public int getAndAdd(final int operand) {
+        final int last = value;
+        this.value += operand;
+        return last;
+    }
+
+    /**
+     * Increments this instance's value by {@code operand}; this method returns the value associated with the instance
+     * immediately prior to the addition operation. This method is not thread safe.
+     *
+     * @param operand the quantity to add, not null
+     * @throws NullPointerException if {@code operand} is null
+     * @return the value associated with this instance immediately before the operand was added
+     * @since 3.5
+     */
+    public int getAndAdd(final Number operand) {
+        final int last = value;
+        this.value += operand.intValue();
+        return last;
+    }
+
+    // shortValue and byteValue rely on Number implementation
+    /**
+     * Returns the value of this MutableInt as an int.
+     *
+     * @return the numeric value represented by this object after conversion to type int.
+     */
+    @Override
+    public int intValue() {
+        return value;
+    }
+
+    /**
+     * Returns the value of this MutableInt as a long.
+     *
+     * @return the numeric value represented by this object after conversion to type long.
+     */
+    @Override
+    public long longValue() {
+        return value;
+    }
+
+    /**
+     * Returns the value of this MutableInt as a float.
+     *
+     * @return the numeric value represented by this object after conversion to type float.
+     */
+    @Override
+    public float floatValue() {
+        return value;
+    }
+
+    /**
+     * Returns the value of this MutableInt as a double.
+     *
+     * @return the numeric value represented by this object after conversion to type double.
+     */
+    @Override
+    public double doubleValue() {
+        return value;
+    }
+
+    /**
+     * Gets this mutable as an instance of Integer.
+     *
+     * @return an Integer instance containing the value from this mutable, never null
+     */
+    public Integer toInteger() {
+        return Integer.valueOf(intValue());
+    }
+
+    /**
+     * Compares this object to the specified object. The result is {@code true} if and only if the argument is
+     * not {@code null} and is a {@link MutableInt} object that contains the same {@code int} value
+     * as this object.
+     *
+     * @param obj  the object to compare with, null returns false
+     * @return {@code true} if the objects are the same; {@code false} otherwise.
+     */
+    @Override
+    public boolean equals(final Object obj) {
+        if (obj instanceof MutableInt) {
+            return value == ((MutableInt) obj).intValue();
+        }
+        return false;
+    }
+
+    /**
+     * Returns a suitable hash code for this mutable.
+     *
+     * @return a suitable hash code
+     */
+    @Override
+    public int hashCode() {
+        return value;
+    }
+
+    /**
+     * Compares this mutable to another in ascending order.
+     *
+     * @param other  the other mutable to compare to, not null
+     * @return negative if this is less, zero if equal, positive if greater
+     */
+    @Override
+    public int compareTo(final MutableInt other) {
+        return NumberUtils.compare(this.value, other.value);
+    }
+
+    /**
+     * Returns the String value of this mutable.
+     *
+     * @return the mutable value as a string
+     */
+    @Override
+    public String toString() {
+        return String.valueOf(value);
+    }
+
+}