ECL0104=Argument({0}) is not an array.
ECL0105=Rethrew {0} as a runtime exception.
ECL0106=IOException occurred, because {0}
ECL0107=InvalidKeyException occurred, because {0}
ECL0108=The path is null.
ECL0109=Could not create a parent directory of {0}
ECL0110=A parent directory of {0} is not a directory.
ECL0111={0} is not a file.
ECL0112=Could not store {0}
ECL0113=NoSuchPaddingException occurred, because {0}

# Return a Response Directly

When you create a **FastAPI** *path operation* you can normally return any data from it: a `dict`, a `list`, a Pydantic model, a database model, etc.

By default, **FastAPI** would automatically convert that return value to JSON using the `jsonable_encoder` explained in [JSON Compatible Encoder](../tutorial/encoder.md){.internal-link target=_blank}.

```

</div>

/// info

There are other formats and tools to define and install package dependencies.

///

### Create the **FastAPI** Code

* Create an `app` directory and enter it.
* Create an empty file `__init__.py`.
* Create a `main.py` file with:

```Python
from typing import Union

from fastapi import FastAPI

app = FastAPI()


@app.get("/")

    public StemmerOverrideItem(final long id, final String input, final String output) {
        this.id = id;
        this.input = input;
        this.output = output;

        if (id == 0) {
            // create
            newInput = input;
            newOutput = output;
        }
    }

    public String getNewInput() {
        return newInput;
    }

    public void setNewInput(final String newInput) {

1. Add an Emulator named `pixel5`, if you don't already have one

```
$ sdkmanager --install "system-images;android-29;google_apis;x86"
$ echo "no" | avdmanager --verbose create avd --force --name "pixel5" --device "pixel" --package "system-images;android-29;google_apis;x86" --tag "google_apis" --abi "x86"
```

2. Run an Emulator using Android Studio or from command line.

```

    return ImmutableSet.of(singleValue);
  }

  @Override
  @J2ktIncompatible // serialization
  @GwtIncompatible // serialization
  Object writeReplace() {
    return SerializedForm.create(this, new int[] {0}, new int[] {0});
  }

        executor.execute(() -> {
            try {
                final Object eventType = dataMap.remove(getParamValue(localParams, "field.event_type", "event_type"));
                if (getParamValue(localParams, "event.create", "create").equals(eventType)
                        || getParamValue(localParams, "event.modify", "modify").equals(eventType)) {
                    // updated file
                    addDocument(localParams, dataMap);

## First Steps

Let's see a very simple example. It will be so simple that it is not very useful, for now.

But this way we can focus on how the **Dependency Injection** system works.

### Create a dependency, or "dependable"

Let's first focus on the dependency.

It is just a function that can take all the same parameters that a *path operation function* can take:

public class MultisetContainsTester<E> extends AbstractMultisetTester<E> {
  @CollectionSize.Require(absent = ZERO)
  public void testContainsAllMultisetIgnoresFrequency() {
    assertTrue(getMultiset().containsAll(getSubjectGenerator().create(e0(), e0(), e0())));
  }

  @CollectionSize.Require(absent = ZERO)
  public void testContainsAllListIgnoresFrequency() {
    assertTrue(getMultiset().containsAll(asList(e0(), e0(), e0())));
  }

    super(false, true, true, true);
  }

  @Override
  TreeBasedTable<String, Integer, Character> makeTable() {
    TreeBasedTable<String, Integer, Character> table = TreeBasedTable.create();
    table.put("a", 1, 'a');
    table.put("z", 1, 'a');
    return table;
  }

  @Override
  protected Map<String, Map<Integer, Character>> makePopulatedMap() {