```Python hl_lines="3"
{!../../docs_src/app_testing/test_main.py!}
```

...and have the code for the tests just like before.

## Testing: extended example

Now let's extend this example and add more details to see how to test different parts.

### Extended **FastAPI** app file

r = s3.select_object_content(
    Bucket='mycsvbucket',
    Key='sampledata/TotalPopulation.csv.gz',
    ExpressionType='SQL',
    Expression="select * from s3object s where s.Location like '%United States%'",
    InputSerialization={
        'CSV': {
            "FileHeaderInfo": "USE",
        },
        'CompressionType': 'GZIP',
    },
    OutputSerialization={'CSV': {}},
)

@REM   MAVEN_SKIP_RC     (Optional) Flag to disable loading of mavenrc files.
@REM -----------------------------------------------------------------------------

@REM Begin all REM lines with '@' in case MAVEN_BATCH_ECHO is 'on'
@echo off
@REM set title of command window
title %0
@REM enable echoing by setting MAVEN_BATCH_ECHO to 'on'
@if "%MAVEN_BATCH_ECHO%"=="on" echo %MAVEN_BATCH_ECHO%

  /**
   * Quasi-implementation of {@link ListIterator} that works from a list of elements and a set of
   * features to support (from the enclosing {@link AbstractIteratorTester} instance). Instead of
   * throwing exceptions like {@link NoSuchElementException} at the appropriate times, it throws
   * {@link PermittedMetaException} instances, which wrap a set of all exceptions that the iterator

                    throw new RuntimeCIFSException(ignored);
                }
            }
        }

        /*
         * If a local hostname was not provided a name like
         * JCIFS34_172_A6 will be dynamically generated for the
         * client. This is primarily (exclusively?) used as a
         * CallingName during session establishment.
         */

   * characters). That is consistent with {@link InetAddress}, but not with various RFCs. If you
   * want to accept ASCII digits only, you can use something like {@code
   * CharMatcher.ascii().matchesAllOf(ipString)}.
   *
   * <p>The scope ID is validated against the interfaces on the machine, which requires permissions
   * under Android.
   *

   *     be unique to the built instance of the ThreadFactory and will be assigned sequentially. For
   *     example, {@code "rpc-pool-%d"} will generate thread names like {@code "rpc-pool-0"}, {@code
   *     "rpc-pool-1"}, {@code "rpc-pool-2"}, etc.
   * @return this for the builder pattern
   */
  @CanIgnoreReturnValue
  public ThreadFactoryBuilder setNameFormat(String nameFormat) {

 * string {@code "Foo<Bar>"}.
 *
 * <p>A {@code CharEscaper} instance is required to be stateless, and safe when used concurrently by
 * multiple threads.
 *
 * <p>Popular escapers are defined as constants in classes like {@link
 * com.google.common.html.HtmlEscapers} and {@link com.google.common.xml.XmlEscapers}. To create
 * your own escapers extend this class and implement the {@link #escape(char)} method.
 *
 * @author Sven Mawson

```

First generate a 256 bit random key via:

```sh
$ cat /dev/urandom | head -c 32 | base64 -
OSMM+vkKUTCvQs9YL/CVMIMt43HFhkUpqJxTmGl6rYw=
```

Now, you can set `MINIO_KMS_SECRET_KEY` like this:

```sh
export MINIO_KMS_SECRET_KEY=my-minio-key:OSMM+vkKUTCvQs9YL/CVMIMt43HFhkUpqJxTmGl6rYw=
```

> You can choose an arbitrary name for the key - instead of `my-minio-key`.

   * copying the CharSequence to a String and then calling getBytes(Charset) on that String, in
   * reality there are optimizations that make the getBytes(Charset) approach considerably faster,
   * at least for commonly used charsets like UTF-8.
   */

  @Override
  @CanIgnoreReturnValue
  public final Hasher putByte(byte b) {
    buffer.put(b);
    munchIfFull();
    return this;
  }

  @Override
  @CanIgnoreReturnValue