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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
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package org.apache.commons.lang3.tuple;

An immutable triple consisting of three Object elements.
Although the implementation is immutable, there is no restriction on the objects that may be stored. If mutable objects are stored in the triple, then the triple itself effectively becomes mutable. The class is also final, so a subclass can not add undesirable behavior.
#ThreadSafe# if all three objects are thread-safe
Type parameters:
<L> – the left element type
<M> – the middle element type
<R> – the right element type
Since:
3.2/**
 * <p>An immutable triple consisting of three {@code Object} elements.</p>
 *
 * <p>Although the implementation is immutable, there is no restriction on the objects
 * that may be stored. If mutable objects are stored in the triple, then the triple
 * itself effectively becomes mutable. The class is also {@code final}, so a subclass
 * can not add undesirable behavior.</p>
 *
 * <p>#ThreadSafe# if all three objects are thread-safe</p>
 *
 * @param <L> the left element type
 * @param <M> the middle element type
 * @param <R> the right element type
 *
 * @since 3.2
 */
public final class ImmutableTriple<L, M, R> extends Triple<L, M, R> {

    
An empty array.
 Consider using emptyArray() to avoid generics warnings. 
Since:
3.10./**
     * An empty array.
     * <p>
     * Consider using {@link #emptyArray()} to avoid generics warnings.
     * </p>
     *
     * @since 3.10.
     */
    public static final ImmutableTriple<?, ?, ?>[] EMPTY_ARRAY = new ImmutableTriple[0];

    
An immutable triple of nulls.
/**
     * An immutable triple of nulls.
     */
    // This is not defined with generics to avoid warnings in call sites.
    @SuppressWarnings("rawtypes")
    private static final ImmutableTriple NULL = of(null, null, null);

    
Serialization version /** Serialization version */
    private static final long serialVersionUID = 1L;

    
Returns the empty array singleton that can be assigned without compiler warning.
Type parameters:
<L> – the left element type
<M> – the middle element type
<R> – the right element type
Returns:
the empty array singleton that can be assigned without compiler warning.
Since:
3.10./**
     * Returns the empty array singleton that can be assigned without compiler warning.
     *
     * @param <L> the left element type
     * @param <M> the middle element type
     * @param <R> the right element type
     * @return the empty array singleton that can be assigned without compiler warning.
     *
     * @since 3.10.
     */
    @SuppressWarnings("unchecked")
    public static <L, M, R> ImmutableTriple<L, M, R>[] emptyArray() {
        return (ImmutableTriple<L, M, R>[]) EMPTY_ARRAY;
    }

    
Returns an immutable triple of nulls.
Type parameters:
<L> – the left element of this triple. Value is null.
<M> – the middle element of this triple. Value is null.
<R> – the right element of this triple. Value is null.
Returns:
an immutable triple of nulls.
Since:
3.6/**
     * Returns an immutable triple of nulls.
     *
     * @param <L> the left element of this triple. Value is {@code null}.
     * @param <M> the middle element of this triple. Value is {@code null}.
     * @param <R> the right element of this triple. Value is {@code null}.
     * @return an immutable triple of nulls.
     * @since 3.6
     */
    public static <L, M, R> ImmutableTriple<L, M, R> nullTriple() {
        return NULL;
    }

    
Obtains an immutable triple of three objects inferring the generic types.
This factory allows the triple to be created using inference to
obtain the generic types.
Params:
left –  the left element, may be null
middle –  the middle element, may be null
right –  the right element, may be null
Type parameters:
<L> – the left element type
<M> – the middle element type
<R> – the right element type
Returns:
a triple formed from the three parameters, not null/**
     * <p>Obtains an immutable triple of three objects inferring the generic types.</p>
     *
     * <p>This factory allows the triple to be created using inference to
     * obtain the generic types.</p>
     *
     * @param <L> the left element type
     * @param <M> the middle element type
     * @param <R> the right element type
     * @param left  the left element, may be null
     * @param middle  the middle element, may be null
     * @param right  the right element, may be null
     * @return a triple formed from the three parameters, not null
     */
    public static <L, M, R> ImmutableTriple<L, M, R> of(final L left, final M middle, final R right) {
        return new ImmutableTriple<>(left, middle, right);
    }
    
Left object /** Left object */
    public final L left;
    
Middle object /** Middle object */
    public final M middle;

    
Right object /** Right object */
    public final R right;

    
Create a new triple instance.
Params:
left –  the left value, may be null
middle – the middle value, may be null
right –  the right value, may be null/**
     * Create a new triple instance.
     *
     * @param left  the left value, may be null
     * @param middle the middle value, may be null
     * @param right  the right value, may be null
     */
    public ImmutableTriple(final L left, final M middle, final R right) {
        super();
        this.left = left;
        this.middle = middle;
        this.right = right;
    }

    //-----------------------------------------------------------------------
    
{@inheritDoc}
/**
     * {@inheritDoc}
     */
    @Override
    public L getLeft() {
        return left;
    }

    
{@inheritDoc}
/**
     * {@inheritDoc}
     */
    @Override
    public M getMiddle() {
        return middle;
    }

    
{@inheritDoc}
/**
     * {@inheritDoc}
     */
    @Override
    public R getRight() {
        return right;
    }
}