And that function takes parameters in the same way that *path operation functions* do.

/// tip

You'll see what other "things", apart from functions, can be used as dependencies in the next chapter.

///

Whenever a new request arrives, **FastAPI** will take care of:

* Calling your dependency ("dependable") function with the correct parameters.

* It takes each **request** that comes to your application.
* It can then do something to that **request** or run any needed code.
* Then it passes the **request** to be processed by the rest of the application (by some *path operation*).
* It then takes the **response** generated by the application (by some *path operation*).

 * as a ByteArrayInputStream.
 * </p>
 *
 * <p>
 * The transform method takes a ResponseData object, checks if it has a response body,
 * and then reads the body into a byte array. This byte array is then set as the data
 * in the ResultData object.
 * </p>
 *
 * <p>
 * The getData method takes an AccessResultData object, checks if the transformer name matches,

import org.apache.maven.artifact.metadata.ArtifactMetadataSource;
import org.apache.maven.artifact.repository.ArtifactRepository;
import org.apache.maven.artifact.resolver.filter.ArtifactFilter;

/**
 * Artifact collector - takes a set of original artifacts and resolves the best versions to use
 * along with their metadata. No artifacts are downloaded.
 */
@Deprecated

			xForwardedFor: []string{"8.8.8.8"},
			xRealIP:       []string{"1.1.1.1"},
		},
	}
	// When X-Forwarded-For and X-Real-IP headers are both present, X-Forwarded-For takes precedence.
	res := GetSourceIP(req)
	if res != "8.8.8.8" {
		t.Errorf("wrong header, xff takes precedence: got %s, want: 8.8.8.8", res)
	}

	// When explicitly disabled, the XFF header is ignored and X-Real-IP is used.
	enableXFFHeader = false
	defer func() {

# `HTTPConnection` class

When you want to define dependencies that should be compatible with both HTTP and WebSockets, you can define a parameter that takes an `HTTPConnection` instead of a `Request` or a `WebSocket`.

You can import it from `fastapi.requests`:

```python
from fastapi.requests import HTTPConnection
```

on 16 drive MinIO deployment. If you use eight data and eight parity drives, the file space usage will be approximately twice, i.e. 100 MiB
file will take 200 MiB space. But, if you use ten data and six parity drives, same 100 MiB file takes around 160 MiB. If you use 14 data and
two parity drives, 100 MiB file takes only approximately 114 MiB.

# Dependencies - `Depends()` and `Security()`

## `Depends()`

Dependencies are handled mainly with the special function `Depends()` that takes a callable.

Here is the reference for it and its parameters.

You can import it directly from `fastapi`:

```python
from fastapi import Depends
```

::: fastapi.Depends

## `Security()`

You can import it directly from `fastapi`:

```python
from fastapi import Request
```

/// tip

When you want to define dependencies that should be compatible with both HTTP and WebSockets, you can define a parameter that takes an `HTTPConnection` instead of a `Request` or a `WebSocket`.

///

  /*
   * TODO(cpovirk): consider higher-level APIs here (say, assertNoRecordsLogged(),
   * getOnlyRecordLogged(), getAndClearLogRecords()...)
   *
   * TODO(cpovirk): consider renaming this method to reflect that it takes a snapshot (and/or return
   * an ImmutableList)
   */
  public List<LogRecord> getStoredLogRecords() {
    synchronized (lock) {
      List<LogRecord> result = new ArrayList<>(list);