In this case, this `__call__` is what **FastAPI** will use to check for additional parameters and sub-dependencies, and this is what will be called to pass a value to the parameter in your *path operation function* later.

## Parameterize the instance { #parameterize-the-instance }

And now, we can use `__init__` to declare the parameters of the instance that we can use to "parameterize" the dependency:

You can start FastAPI CLI with the *CLI Option* `--forwarded-allow-ips` and pass the IP addresses that should be trusted to read those forwarded headers.

If you set it to `--forwarded-allow-ips="*"` it would trust all the incoming IPs.

If your **server** is behind a trusted **proxy** and only the proxy talks to it, this would make it accept whatever is the IP of that **proxy**.

<div class="termy">

of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in

of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in

a copy of this software and associated documentation files (the
"Software"), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:

The above copyright notice and this permission notice shall be

of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in

try (Response response = client.newCall(request).execute()) {
  // Consume and discard the response body.
  response.body().source().readByteString();
}

System.out.println("REQUEST 2 (pooled connection)");
try (Response response = client.newCall(request).execute()) {
  // Consume and discard the response body.
  response.body().source().readByteString();
}
```

And the listener prints the corresponding events:

```

Make sure you create a [virtual environment](../virtual-environments.md){.internal-link target=_blank}, activate it, and then install it, for example:

<div class="termy">

```console
$ pip install pytest

---> 100%
```

</div>

It will detect the files and tests automatically, execute them, and report the results back to you.

Run the tests with:

<div class="termy">

```console
$ pytest

    }

    // Edge/null/empty: message-only constructor should propagate message and set unsuccessful status
    @ParameterizedTest
    @NullSource
    @ValueSource(strings = { "", " ", "simple", "with unicode Ω≈ç√", "long-0123456789-abcdefghijklmnopqrstuvwxyz" })
    @DisplayName("Message-only ctor: propagates message and unsuccessful status")
    void messageOnlyConstructor_setsMessage_andUnsuccessfulStatus(String msg) {

 * either express or implied. See the License for the specific language
 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.app.service;

/**
 * Abstract base class for Fess application services.
 * This class provides common functionality and utilities for service implementations
 * throughout the Fess search application.
 */
public abstract class FessAppService {

    /**