this.executorServiceOrNull = executorService
  }

  internal fun enqueue(call: AsyncCall) {
    synchronized(this) {
      readyAsyncCalls.add(call)

      // Mutate the AsyncCall so that it shares the AtomicInteger of an existing running call to
      // the same host.
      if (!call.call.forWebSocket) {
        val existingCall = findExistingCallWithHost(call.host)

Now, let's imagine your organization gave you the `app/internal/admin.py` file.

It contains an `APIRouter` with some admin *path operations* that your organization shares between several projects.

For this example it will be super simple. But let's say that because it is shared with other projects in the organization, we cannot modify it and add a `prefix`, `dependencies`, `tags`, etc. directly to the `APIRouter`:

### [Addresses](https://square.github.io/okhttp/4.x/okhttp/okhttp3/-address/)

Addresses specify a webserver (like `github.com`) and all of the **static** configuration necessary to connect to that server: the port number, HTTPS settings, and preferred network protocols (like HTTP/2).

	// metacacheBlockSize is the number of file/directory entries to have in each block.
	metacacheBlockSize = 5000

	// metacacheSharePrefix controls whether prefixes on dirty paths are always shared.
	// This will make `test/a` and `test/b` share listings if they are concurrent.
	// Enabling this will make cache sharing more likely and cause less IO,
	// but may cause additional latency to some calls.
	metacacheSharePrefix = false
)

        // Normal extensions should be allowed
        assertEquals("\\share\\file.txt", validator.validatePath("\\share\\file.txt"));
        assertEquals("\\share\\document.docx", validator.validatePath("\\share\\document.docx"));
        assertEquals("\\share\\archive.tar.gz", validator.validatePath("\\share\\archive.tar.gz"));
    }

    @Test
    public void testInternationalCharacters() throws Exception {

        SmbResourceLocatorImpl a = locator("smb://server/share/dir/file.txt");
        assertEquals("file.txt", a.getName());

        // share name with trailing slash when only share present
        SmbResourceLocatorImpl b = locator("smb://server/share/");
        assertEquals("share/", b.getName());

        // host when no path/share
        SmbResourceLocatorImpl c = locator("smb://server/");

    
    SmbFile dir = new SmbFile("smb://server/share/testdir/", context);
    
    // First listing should hit the server
    long start1 = System.currentTimeMillis();
    SmbFile[] files1 = dir.listFiles();
    long time1 = System.currentTimeMillis() - start1;
    
    // Second listing should use cache (much faster)
    long start2 = System.currentTimeMillis();

            "share, " // empty service
    })
    void getSmbTree_invalid(String share, String service) {
        doThrow(new IllegalArgumentException("invalid share/service")).when(session).getSmbTree(eq(share), eq(service));

        IllegalArgumentException ex = assertThrows(IllegalArgumentException.class, () -> session.getSmbTree(share, service));
        assertTrue(ex.getMessage().contains("invalid"));

            assertEquals("smb1://server/share/", new SmbFile("smb1://server/share/file.txt").getParent());
            // Test parent of a directory
            assertEquals("smb1://server/share/", new SmbFile("smb1://server/share/dir/").getParent());
            // Test parent of a share
            assertEquals("smb1://server/", new SmbFile("smb1://server/share/").getParent());
            // Test parent of a server

      sourceCount++
    }

    return RelaySource()
  }

  internal inner class RelaySource : Source {
    private val timeout = Timeout()

    /** The operator to read and write the shared file. Null if this source is closed. */
    private var fileOperator: FileOperator? = FileOperator(file!!.channel)

    /** The next byte to read. This is always less than or equal to [upstreamPos]. */