if (existing != null) {
          return existing;
        }
      }
      drainQueue();
      return created;
    }

    // N.B. Draining the queue is only necessary to ensure that we don't accumulate empty references
    // in the array. We could skip this if we decide we don't care about holding on to Reference
    // objects indefinitely.

     *
     * @return create cancel request
     */
    CommonServerMessageBlockRequest createCancel();

    /**
     * Checks if chaining is allowed with the next request.
     *
     * @param next the next request in the chain
     * @return whether to allow chaining
     */
    boolean allowChain(CommonServerMessageBlockRequest next);

    /**
     * Sets the tree ID.
     *
     * @param t the tree ID to set

        assertEquals((byte) 0xFF, buf[1], "AndX command should be 0xFF when no chaining");
        assertEquals((byte) 0x00, buf[2], "Reserved byte must be 0");
        assertEquals((byte) 0xDE, buf[3], "Sentinel low offset when no chaining");
        assertEquals((byte) 0xDE, buf[4], "Sentinel high offset when no chaining");
        assertNull(block.andx, "andx should be cleared when not chaining");
    }

    @Test

            return 0;
        }
    }

    @Test
    @DisplayName("open(): invalid URL path without trailing slash throws SmbException")
    void invalidUrlPathThrows() throws Exception {
        // Override the default setup for this specific test
        URL invalidUrl = new URL("smb://server/share/dir"); // no trailing '/'
        when(locator.getURL()).thenReturn(invalidUrl);

        SmbException ex =

    public void test_expiry_validValue() {
        long newExpiry = 60L * 24 * 60 * 60 * 1000L; // 60 days
        PurgeThumbnailJob result = purgeThumbnailJob.expiry(newExpiry);

        // Test method chaining
        assertSame(purgeThumbnailJob, result);
        // Test value was set
        assertEquals(newExpiry, purgeThumbnailJob.getExpiry());
    }

    // Test expiry setter with zero value (should not change)

            //     || byte1 == (byte) 0xF4 && byte2 > (byte) 0x8F)
            || (((byte1 << 28) + (byte2 - (byte) 0x90)) >> 30) != 0
            // Third byte trailing-byte test
            || bytes[index++] > (byte) 0xBF
            // Fourth byte trailing-byte test
            || bytes[index++] > (byte) 0xBF) {
          return false;
        }
      }
    }
  }

        assertNotNull(r1);
        assertEquals("foo/", r1.getName(), "First child name should match with trailing slash");

        assertTrue(it.hasNext(), "Expected second element available");
        SmbResource r2 = it.next();
        assertNotNull(r2);
        assertEquals("bar/", r2.getName(), "Second child name should match with trailing slash");

        // End of iteration behavior

     *  wire format so that we can observe only the bytes written by a method.
     */
    private static byte[] newBuffer(int length) {
        // initialise with distinct pattern to detect unused trailing bytes
        byte[] buf = new byte[length];
        Arrays.fill(buf, (byte) 0xFF);
        return buf;
    }

    @Test
    @DisplayName("constructor initialises command and parameters correctly")

		{"␀␁␂␃␄␅␆␇␈␉␊␋␌␍␎␏␐␑␒␓␔␕␖␗␘␙␚␛␜␝␞␟␡", true},
		{"trailing VT␋/trailing VT␋", true},
		{"␋leading VT/␋leading VT", true},
		{"~leading tilde", true},
		{"\rleading CR", true},
		{"\nleading LF", true},
		{"\tleading HT", true},
		{"trailing CR\r", true},
		{"trailing LF\n", true},
		{"trailing HT\t", true},
		// cases for which test should fail.
		// passing invalid object names.

		{
			path:   "/bucket/object/1/",
			bucket: "bucket",
			object: "object/1/",
		},
		// Test case 5 object has many trailing separators.
		{
			path:   "/bucket/object/1///",
			bucket: "bucket",
			object: "object/1///",
		},
		// Test case 6 object has only trailing separators.
		{
			path:   "/bucket/object///////",
			bucket: "bucket",
			object: "object///////",
		},