# Sub-dependencies { #sub-dependencies }

You can create dependencies that have **sub-dependencies**.

They can be as **deep** as you need them to be.

**FastAPI** will take care of solving them.

## First dependency "dependable" { #first-dependency-dependable }

You could create a first dependency ("dependable") like:

{* ../../docs_src/dependencies/tutorial005_an_py310.py hl[8:9] *}

   Please inform us in your report email whether MinIO should mention your contribution w.r.t. fixing
   the security issue. By default MinIO will **not** publish this information to protect your privacy.

This process can take some time, especially when coordination is required with maintainers of other projects.
Every effort will be made to handle the bug in as timely a manner as possible, however it's important that we

    }
  }

  /** Manages a {@link BlockingQueue} and associated timings for a {@code take} call. */
  private static final class TimedTakeQueue {
    final BlockingQueue<String> queue;
    final Completion completed;

    /**
     * Creates a {@link EnableReads} which insert an element for a {@code take} to receive in {@code
     * countdownInMillis}.
     */

### Technical Details: `root_path` { #technical-details-root-path }

When you mount a sub-application as described above, FastAPI will take care of communicating the mount path for the sub-application using a mechanism from the ASGI specification called a `root_path`.

That way, the sub-application will know to use that path prefix for the docs UI.

		f:      formatBZ2,
	},
}

type untarOptions struct {
	ignoreDirs bool
	ignoreErrs bool
	prefixAll  string
}

// disconnectReader will ensure that no reads can take place on
// the upstream reader after close has been called.
type disconnectReader struct {
	r  io.Reader
	mu sync.Mutex
}

func (d *disconnectReader) Read(p []byte) (n int, err error) {
	d.mu.Lock()

    ]
}
```

## Recap { #recap }

Declare headers with `Header`, using the same common pattern as `Query`, `Path` and `Cookie`.

That's what makes it possible to have multiple automatic interactive documentation interfaces, code generation, etc.

OpenAPI has a way to define multiple security "schemes".

By using them, you can take advantage of all these standard-based tools, including these interactive documentation systems.

OpenAPI defines the following security schemes:

* `apiKey`: an application specific key that can come from:

# Query Parameters and String Validations { #query-parameters-and-string-validations }

**FastAPI** allows you to declare additional information and validation for your parameters.

Let's take this application as example:

{* ../../docs_src/query_params_str_validations/tutorial001_py310.py hl[7] *}

///

The only thing the function returned by `GzipRequest.get_route_handler` does differently is convert the `Request` to a `GzipRequest`.

Doing this, our `GzipRequest` will take care of decompressing the data (if necessary) before passing it to our *path operations*.

After that, all of the processing logic is the same.

        validator.addToBlacklist("\\share\\test");
        validator.addToWhitelist("\\share\\test");

        // Blacklist should take priority
        try {
            validator.validatePath("\\share\\test\\file.txt");
            fail("Blacklist should take priority over whitelist");
        } catch (SmbException e) {
            assertTrue(e.getMessage().contains("not allowed"));
        }
    }