public Hasher putByte(byte b) {
      ensureCapacity(Byte.BYTES);
      buffer.put(b);
      return this;
    }

    @Override
    public Hasher putBytes(byte[] bytes, int off, int len) {
      ensureCapacity(len);
      buffer.put(bytes, off, len);
      return this;
    }

    @Override
    public Hasher putBytes(ByteBuffer bytes) {
      ensureCapacity(bytes.remaining());
      buffer.put(bytes);

    }
  }

  public void testEnsureCapacity() {
    assertThat(Shorts.ensureCapacity(EMPTY, 0, 1)).isSameInstanceAs(EMPTY);
    assertThat(Shorts.ensureCapacity(ARRAY1, 0, 1)).isSameInstanceAs(ARRAY1);
    assertThat(Shorts.ensureCapacity(ARRAY1, 1, 1)).isSameInstanceAs(ARRAY1);
    assertThat(Shorts.ensureCapacity(ARRAY1, 2, 1))
        .isEqualTo(new short[] {(short) 1, (short) 0, (short) 0});
  }

  public void setUp() {
    // precalculate some random strings of ascii characters.
    StringBuilder sb = new StringBuilder();
    Random random = new Random(0xdeadbeef); // for unpredictable but reproducible behavior
    sb.ensureCapacity(size);
    for (int k = 0; k < size; k++) {
      // [9-127) includes all ascii non-control characters
      sb.append((char) (random.nextInt(127 - 9) + 9));
    }
    data = sb.toString();
  }

    }
  }

  public void testEnsureCapacity() {
    assertThat(Bytes.ensureCapacity(EMPTY, 0, 1)).isSameInstanceAs(EMPTY);
    assertThat(Bytes.ensureCapacity(ARRAY1, 0, 1)).isSameInstanceAs(ARRAY1);
    assertThat(Bytes.ensureCapacity(ARRAY1, 1, 1)).isSameInstanceAs(ARRAY1);
    assertThat(Bytes.ensureCapacity(ARRAY1, 2, 1))
        .isEqualTo(new byte[] {(byte) 1, (byte) 0, (byte) 0});
  }

    }
  }

  public void testEnsureCapacity() {
    assertThat(Booleans.ensureCapacity(EMPTY, 0, 1)).isSameInstanceAs(EMPTY);
    assertThat(Booleans.ensureCapacity(ARRAY_FALSE, 0, 1)).isSameInstanceAs(ARRAY_FALSE);
    assertThat(Booleans.ensureCapacity(ARRAY_FALSE, 1, 1)).isSameInstanceAs(ARRAY_FALSE);
    assertThat(Booleans.ensureCapacity(new boolean[] {true}, 2, 1))
        .isEqualTo(new boolean[] {true, false, false});
  }

  }

  public void testEnsureCapacity() {
    assertThat(Chars.ensureCapacity(EMPTY, 0, 1)).isSameInstanceAs(EMPTY);
    assertThat(Chars.ensureCapacity(ARRAY1, 0, 1)).isSameInstanceAs(ARRAY1);
    assertThat(Chars.ensureCapacity(ARRAY1, 1, 1)).isSameInstanceAs(ARRAY1);
    assertThat(Chars.ensureCapacity(ARRAY1, 2, 1))
        .isEqualTo(new char[] {(char) 1, (char) 0, (char) 0});
  }

    }
  }

  public void testEnsureCapacity() {
    assertThat(Doubles.ensureCapacity(EMPTY, 0, 1)).isSameInstanceAs(EMPTY);
    assertThat(Doubles.ensureCapacity(ARRAY1, 0, 1)).isSameInstanceAs(ARRAY1);
    assertThat(Doubles.ensureCapacity(ARRAY1, 1, 1)).isSameInstanceAs(ARRAY1);
    assertThat(Arrays.equals(new double[] {1.0, 0.0, 0.0}, Doubles.ensureCapacity(ARRAY1, 2, 1)))
        .isTrue();
  }

    }
  }

  public void testEnsureCapacity() {
    assertThat(Ints.ensureCapacity(EMPTY, 0, 1)).isSameInstanceAs(EMPTY);
    assertThat(Ints.ensureCapacity(ARRAY1, 0, 1)).isSameInstanceAs(ARRAY1);
    assertThat(Ints.ensureCapacity(ARRAY1, 1, 1)).isSameInstanceAs(ARRAY1);
    assertThat(Ints.ensureCapacity(ARRAY1, 2, 1)).isEqualTo(new int[] {(int) 1, (int) 0, (int) 0});
  }

  public void setUp() {
    charset = Charset.forName(charsetName);
    StringBuilder sb = new StringBuilder();
    Random random = new Random(0xdeadbeef); // for unpredictable but reproducible behavior
    sb.ensureCapacity(size);
    for (int k = 0; k < size; k++) {
      // [9-127) includes all ascii non-control characters
      sb.append((char) (random.nextInt(127 - 9) + 9));
    }
    String string = sb.toString();

      }
    }

    /** Adds e to the insertion-order array of deduplicated elements. Calls ensureCapacity. */
    final void addDedupedElement(E e) {
      ensureCapacity(distinct + 1);
      dedupedElements[distinct++] = e;
    }

    /**
     * Adds e to this SetBuilderImpl, returning the updated result. Only use the returned