builder.putAll("foo", Arrays.asList(1, 2, 3));
    builder.putAll("bar", Arrays.asList(4, 5));
    builder.putAll("foo", Arrays.asList(6, 7));
    Multimap<String, Integer> multimap = builder.build();
    assertEquals(ImmutableSet.of(1, 2, 3, 6, 7), multimap.get("foo"));
    assertEquals(ImmutableSet.of(4, 5), multimap.get("bar"));
    assertEquals(7, multimap.size());
  }

### Start Dex

```
~ ./bin/dex serve dex.yaml
time="2020-07-12T20:45:50Z" level=info msg="config issuer: http://127.0.0.1:5556/dex"
time="2020-07-12T20:45:50Z" level=info msg="config storage: sqlite3"
time="2020-07-12T20:45:50Z" level=info msg="config static client: Example App"
time="2020-07-12T20:45:50Z" level=info msg="config connector: mock"
time="2020-07-12T20:45:50Z" level=info msg="config connector: local passwords enabled"

    builder.putAll("foo", Arrays.asList(1, 2, 3));
    builder.putAll("bar", Arrays.asList(4, 5));
    builder.putAll("foo", Arrays.asList(6, 7));
    Multimap<String, Integer> multimap = builder.build();
    assertThat(multimap.get("foo")).containsExactly(1, 2, 3, 6, 7).inOrder();
    assertThat(multimap.get("bar")).containsExactly(4, 5).inOrder();
    assertEquals(7, multimap.size());
  }

    builder.putAll("foo", Arrays.asList(1, 2, 3));
    builder.putAll("bar", Arrays.asList(4, 5));
    builder.putAll("foo", Arrays.asList(6, 7));
    Multimap<String, Integer> multimap = builder.build();
    assertEquals(ImmutableSet.of(1, 2, 3, 6, 7), multimap.get("foo"));
    assertEquals(ImmutableSet.of(4, 5), multimap.get("bar"));
    assertEquals(7, multimap.size());
  }

            validator.safeAdd(Integer.MIN_VALUE, -1);
        });
    }

    @Test
    public void testSafeMultiply() throws Exception {
        assertEquals(20, validator.safeMultiply(4, 5));
        assertEquals(-20, validator.safeMultiply(-4, 5));
        assertEquals(0, validator.safeMultiply(0, 1000));
    }

    @Test
    public void testSafeMultiplyOverflow() throws Exception {

        @Override
        protected ListIterator<Entry<String, Integer>> newTargetIterator() {
          multimap = create();
          multimap.putAll("foo", asList(2, 3));
          multimap.putAll("bar", asList(4, 5));
          multimap.put("foo", 6);
          return multimap.entries().listIterator(startIndex);
        }

        @Override
        protected void verify(List<Entry<String, Integer>> elements) {

            .concurrencyLevel(1)
            .maximumWeight(45)
            .weigher(intKeyWeigher())
            .build(loader);
    CacheTesting.warmUp(cache, 0, 10);
    Set<Integer> keySet = cache.asMap().keySet();
    assertThat(keySet).containsExactly(0, 1, 2, 3, 4, 5, 6, 7, 8, 9);

    // add an at-the-maximum-weight entry
    getAll(cache, asList(45));
    CacheTesting.drainRecencyQueues(cache);

        TransCallNamedPipeResponse response3 = new TransCallNamedPipeResponse(mockConfig, outputBuffer3);
        System.arraycopy(sourceData, 0, buffer, 45, sourceData.length);
        int result3 = response3.readDataWireFormat(buffer, 45, sourceData.length);
        assertEquals(sourceData.length, result3);
    }

    @Test
    void testConstructorWithNullBuffer() {

- Update `SmbFile` caching logic to use leases
- Add lease break handling in `SmbTransport`

---

### Phase 2: Persistent Handles
**Priority: HIGH** | **Estimated Effort: 4-5 weeks**

Persistent handles allow connections to survive network interruptions and server failovers.

#### 2.1 Core Persistent Handle Infrastructure
```
Package: jcifs.internal.smb2.persistent

            (byte) 26, (byte) 18, (byte) 10, (byte) 2, (byte) 59, (byte) 51, (byte) 43, (byte) 35, (byte) 62, (byte) 54, (byte) 46,
            (byte) 38, (byte) 30, (byte) 22, (byte) 14, (byte) 6, (byte) 61, (byte) 53, (byte) 45, (byte) 37, (byte) 29, (byte) 21,
            (byte) 13, (byte) 5, (byte) 60, (byte) 52, (byte) 44, (byte) 36, (byte) 28, (byte) 20, (byte) 12, (byte) 4, (byte) 27,
            (byte) 19, (byte) 11, (byte) 3 };