future. (Previously, we sometimes removed such APIs after a deprecation
    period. The last release to remove non-`@Beta` APIs was Guava 21.0.) Even
    `@Deprecated` APIs will remain (again, unless they are `@Beta`). We have no
    plans to start removing things again, but officially, we're leaving our
    options open in case of surprises (like, say, a serious security problem).

3.  Guava has one dependency that is needed for linkage at runtime:

This is very useful when you need to:

* Have shared logic (the same code logic again and again).
* Share database connections.
* Enforce security, authentication, role requirements, etc.
* And many other things...

All these, while minimizing code repetition.

## First Steps { #first-steps }

{* ../../docs_src/sql_databases/tutorial002_an_py310.py ln[96:103] hl[101] *}

### Run the App Again { #run-the-app-again }

You can run the app again:

<div class="termy">

```console
$ fastapi dev main.py

<span style="color: green;">INFO</span>:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
```

</div>

package cmd

import "strconv"

func _() {
	// An "invalid array index" compiler error signifies that the constant values have changed.
	// Re-run the stringer command to generate them again.
	var x [1]struct{}
	_ = x[authTypeUnknown-0]
	_ = x[authTypeAnonymous-1]
	_ = x[authTypePresigned-2]
	_ = x[authTypePresignedV2-3]
	_ = x[authTypePostPolicy-4]
	_ = x[authTypeStreamingSigned-5]

package cmd

import "strconv"

func _() {
	// An "invalid array index" compiler error signifies that the constant values have changed.
	// Re-run the stringer command to generate them again.
	var x [1]struct{}
	_ = x[rebalanceMetricRebalanceBuckets-0]
	_ = x[rebalanceMetricRebalanceBucket-1]
	_ = x[rebalanceMetricRebalanceObject-2]
	_ = x[rebalanceMetricRebalanceRemoveObject-3]

package cmd

import "strconv"

func _() {
	// An "invalid array index" compiler error signifies that the constant values have changed.
	// Re-run the stringer command to generate them again.
	var x [1]struct{}
	_ = x[formatUnknown-0]
	_ = x[formatGzip-1]
	_ = x[formatZstd-2]
	_ = x[formatLZ4-3]
	_ = x[formatS2-4]
	_ = x[formatBZ2-5]
}

const _format_name = "UnknownGzipZstdLZ4S2BZ2"

package cmd

import "strconv"

func _() {
	// An "invalid array index" compiler error signifies that the constant values have changed.
	// Re-run the stringer command to generate them again.
	var x [1]struct{}
	_ = x[lcEventSrc_None-0]
	_ = x[lcEventSrc_Heal-1]
	_ = x[lcEventSrc_Scanner-2]
	_ = x[lcEventSrc_Decom-3]
	_ = x[lcEventSrc_Rebal-4]
	_ = x[lcEventSrc_s3HeadObject-5]

   * worker, and then the first thread's call to delegate.execute() returns. Without this counter,
   * it would observe the QUEUING state and set it to QUEUED, and the worker would never be
   * scheduled again for future submissions.
   */
  @GuardedBy("queue")
  private long workerRunCount = 0;

  @RetainedWith private final QueueWorker worker = new QueueWorker();

  /** Use {@link MoreExecutors#newSequentialExecutor} */

<div class="termy">

```console
// Here we don't set the env var yet
$ python main.py

// As we didn't set the env var, we get the default value

Hello World from Python

// But if we create an environment variable first
$ export MY_NAME="Wade Wilson"

// And then call the program again
$ python main.py

// Now it can read the environment variable

Hello Wade Wilson from Python
```

package cmd

import "strconv"

func _() {
	// An "invalid array index" compiler error signifies that the constant values have changed.
	// Re-run the stringer command to generate them again.
	var x [1]struct{}
	_ = x[storageMetricMakeVolBulk-0]
	_ = x[storageMetricMakeVol-1]
	_ = x[storageMetricListVols-2]
	_ = x[storageMetricStatVol-3]
	_ = x[storageMetricDeleteVol-4]
	_ = x[storageMetricWalkDir-5]