public void removeAllZeros() {
    map.values().removeIf(x -> x == 0);
  }

  /**
   * Returns the sum of all values in this map.
   *
   * <p>This method is not atomic: the sum may or may not include other concurrent operations.
   */
  public long sum() {
    return map.values().stream().mapToLong(Long::longValue).sum();
  }

  @LazyInit private transient @Nullable Map<K, Long> asMap;

        for (int i = 0; i < elements.length; i++) {
          // add to either; sum should contain all
          if (i % 2 == 0) {
            multiset1.add(elements[i]);
          } else {
            multiset2.add(elements[i]);
          }
        }
        return sum(multiset1, multiset2);
      }
    };
  }

  private static TestStringMultisetGenerator differenceGenerator() {

        assertEquals("test", testValue);
    }

    // Additional test for coverage
    public void test_additionalCoverage() {
        int a = 5;
        int b = 10;
        int sum = a + b;
        assertEquals(15, sum);

        String str = "Hello";
        assertTrue(str.startsWith("H"));
        assertTrue(str.endsWith("o"));
        assertEquals(5, str.length());
    }

        assertEquals("test", testValue);
    }

    // Additional test for coverage
    public void test_additionalCoverage() {
        int a = 5;
        int b = 10;
        int sum = a + b;
        assertEquals(15, sum);

        String str = "Hello";
        assertTrue(str.startsWith("H"));
        assertTrue(str.endsWith("o"));
        assertEquals(5, str.length());
    }

        assertEquals("test", testValue);
    }

    // Additional test for coverage
    public void test_additionalCoverage() {
        int a = 5;
        int b = 10;
        int sum = a + b;
        assertEquals(15, sum);

        String str = "Hello";
        assertTrue(str.startsWith("H"));
        assertTrue(str.endsWith("o"));
        assertEquals(5, str.length());
    }

        assertEquals("test", testValue);
    }

    // Additional test for coverage
    public void test_additionalCoverage() {
        int a = 5;
        int b = 10;
        int sum = a + b;
        assertEquals(15, sum);

        String str = "Hello";
        assertTrue(str.startsWith("H"));
        assertTrue(str.endsWith("o"));
        assertEquals(5, str.length());
    }

        assertEquals("test", testValue);
    }

    // Additional test for coverage
    public void test_additionalCoverage() {
        int a = 5;
        int b = 10;
        int sum = a + b;
        assertEquals(15, sum);

        String str = "Hello";
        assertTrue(str.startsWith("H"));
        assertTrue(str.endsWith("o"));
        assertEquals(5, str.length());
    }

        assertEquals("test", testValue);
    }

    // Additional test for coverage
    public void test_additionalCoverage() {
        int a = 5;
        int b = 10;
        int sum = a + b;
        assertEquals(15, sum);

        String str = "Hello";
        assertTrue(str.startsWith("H"));
        assertTrue(str.endsWith("o"));
        assertEquals(5, str.length());
    }

        assertEquals("test", testValue);
    }

    // Additional test for coverage
    public void test_additionalCoverage() {
        int a = 5;
        int b = 10;
        int sum = a + b;
        assertEquals(15, sum);

        String str = "Hello";
        assertTrue(str.startsWith("H"));
        assertTrue(str.endsWith("o"));
        assertEquals(5, str.length());
    }

        assertEquals("test", testValue);
    }

    // Additional test for coverage
    public void test_additionalCoverage() {
        int a = 5;
        int b = 10;
        int sum = a + b;
        assertEquals(15, sum);

        String str = "Hello";
        assertTrue(str.startsWith("H"));
        assertTrue(str.endsWith("o"));
        assertEquals(5, str.length());
    }