* This allows adding extra code after a dependency is done. It can be used, for example, to close database connections.
    * Dependencies with `yield` can be normal or `async`, **FastAPI** will run normal dependencies in a threadpool.
    * They can be combined with normal dependencies.
    * It's possible to have arbitrary trees/levels of dependencies with `yield` and exit steps are handled in the correct order automatically.

var (
	driveUsedBytesMD = NewGaugeMD(driveUsedBytes,
		"Total storage used on a drive in bytes", allDriveLabels...)
	driveFreeBytesMD = NewGaugeMD(driveFreeBytes,
		"Total storage free on a drive in bytes", allDriveLabels...)
	driveTotalBytesMD = NewGaugeMD(driveTotalBytes,
		"Total storage available on a drive in bytes", allDriveLabels...)
	driveUsedInodesMD = NewGaugeMD(driveUsedInodes,
		"Total used inodes on a drive", allDriveLabels...)

example with 1024 drives - 4, 8, 16 are GCD factors. With 16 drives we get a total of 64 possible sets, with 8 drives we get a total of 128 possible sets, with 4 drives we get a total of 256 possible sets. So algorithm automatically chooses 64 sets, which is *16* 64 = 1024* drives in total.

- *If total number of nodes are of odd number then GCD algorithm provides affinity towards odd number erasure sets to provide for uniform distribution across nodes*. This is to ensure that same number of drives...

# Extending OpenAPI

There are some cases where you might need to modify the generated OpenAPI schema.

In this section you will see how.

## The normal process

The normal (default) process, is as follows.

A `FastAPI` application (instance) has an `.openapi()` method that is expected to return the OpenAPI schema.

Prefer to use the `Annotated` version if possible.

///

```Python hl_lines="17"
{!> ../../docs_src/dependencies/tutorial006.py!}
```

////

These dependencies will be executed/solved the same way as normal dependencies. But their value (if they return any) won't be passed to your *path operation function*.

/// tip

Some editors check for unused function parameters, and show them as errors.

	// Retrieves information about the amount of space that is available on a disk volume,
	// which is the total amount of space, the total amount of free space, and the total
	// amount of free space available to the user that is associated with the calling thread.
	GetDiskFreeSpaceEx = kernel32.NewProc("GetDiskFreeSpaceExW")

	internodeRecvBytesTotal   MetricName = "recv_bytes_total"
)

var (
	internodeErrorsTotalMD = NewCounterMD(internodeErrorsTotal,
		"Total number of failed internode calls")
	internodeDialedErrorsTotalMD = NewCounterMD(internodeDialErrorsTotal,
		"Total number of internode TCP dial timeouts and errors")
	internodeDialAvgTimeNanosMD = NewGaugeMD(internodeDialAvgTimeNanos,

/**
 * Maven encrypt CLI "new-gen".
 */
public class MavenEncCling extends ClingSupport<EncryptOptions, EncryptInvokerRequest> {
    /**
     * "Normal" Java entry point. Note: Maven uses ClassWorld Launcher and this entry point is NOT used under normal
     * circumstances.
     */
    public static void main(String[] args) throws IOException {
        int exitCode = new MavenEncCling().run(args);

  static final int SIGNIFICAND_BITS = 52;

  static final int EXPONENT_BIAS = 1023;

  /** The implicit 1 bit that is omitted in significands of normal doubles. */
  static final long IMPLICIT_BIT = SIGNIFICAND_MASK + 1;

  static long getSignificand(double d) {
    checkArgument(isFinite(d), "not a normal value");
    int exponent = getExponent(d);
    long bits = doubleToRawLongBits(d);
    bits &= SIGNIFICAND_MASK;

# OpenAPI Webhooks

There are cases where you want to tell your API **users** that your app could call *their* app (sending a request) with some data, normally to **notify** of some type of **event**.

This means that instead of the normal process of your users sending requests to your API, it's **your API** (or your app) that could **send requests to their system** (to their API, their app).

This is normally called a **webhook**.

## Webhooks steps