content: /*
   * The Alluxio Open Foundation licenses this work under the Apache License, version 2.0
   * (the "License"). You may not use this work except in compliance with the License, which is
   * available at www.apache.org/licenses/LICENSE-2.0
   *
   * This software is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
   * either express or implied, as more fully set forth in the License.
   *
   * See the NOTICE file distributed with this work for information regarding copyright ownership.
   */
  
  package alluxio.collections;
  
  import com.google.common.base.Objects;
  
  import javax.annotation.concurrent.NotThreadSafe;
  
  /**
   * A pair representation defined by two elements (of type First and type Second).
   *
   * @param <T1> the first element of the Pair
   * @param <T2> the second element of the Pair
   */
  @NotThreadSafe
  public class Pair<T1, T2> {
    private T1 mFirst;
    private T2 mSecond;
  
    /**
     * Constructs and initializes a Pair specified by the two input elements.
     *
     * @param first the first element of the pair (of type First)
     * @param second the second element of the pair (of type Second)
     */
    public Pair(T1 first, T2 second) {
      mFirst = first;
      mSecond = second;
    }
  
    /**
     * Default constructor for deserialization.
     */
    public Pair() {
    }
  
    @Override
    public boolean equals(Object o) {
      if (o == null) {
        return false;
      }
      if (this == o) {
        return true;
      }
      if (!(o instanceof Pair<?, ?>)) {
        return false;
      }
      Pair that = (Pair) o;
  
      return Objects.equal(mFirst, that.mFirst)
          && Objects.equal(mSecond, that.mSecond);
    }
  
    /**
     * @return the first element of the pair
     */
    public T1 getFirst() {
      return mFirst;
    }
  
    /**
     * @return the second element of the pair
     */
    public T2 getSecond() {
      return mSecond;
    }
  
    @Override
    public int hashCode() {
      return Objects.hashCode(mFirst, mSecond);
    }
  
    /**
     * Set the first value.
     *
     * @param first the value to be set
     */
    public void setFirst(T1 first) {
      mFirst = first;
    }
  
    /**
     * Set the second value.
     *
     * @param second the value to be set
     */
    public void setSecond(T2 second) {
      mSecond = second;
    }
  
    @Override
    public String toString() {
      return new StringBuilder().append("Pair(").append(mFirst).append(",").append(mSecond)
          .append(")").toString();
    }
  }
  