//          automatic skipping of dummy input operations is performed.
//  ninputs - number of elements in `inputs` array
//  inputs - array of TF_Outputs that specify the inputs to the function.
//           If `ninputs` is zero (the function takes no inputs), `inputs`
//           can be null. The names used for function inputs are normalized

The key factor is that a dependency should be a "callable".

A "**callable**" in Python is anything that Python can "call" like a function.

So, if you have an object `something` (that might _not_ be a function) and you can "call" it (execute it) like:

```Python
something()
```

or

```Python
something(some_argument, some_keyword_argument="foo")
```

then it is a "callable".

// aggregation.
//
// Aggregation functions - An expression that involves aggregation of
// rows in some manner. Requires all input rows to be processed,
// before a result is returned.
//
// Row function - An expression that depends on a value in the
// row. They have an output for each input row.
//
// Some types of a queries are not valid. For example, an aggregation

### Abhängigkeiten mit `yield` und `scope` { #dependencies-with-yield-and-scope }

In Version 0.121.0 hat FastAPI Unterstützung für `Depends(scope="function")` für Abhängigkeiten mit `yield` hinzugefügt.

Mit `Depends(scope="function")` wird der Exit-Code nach `yield` direkt nach dem Ende der *Pfadoperation-Funktion* ausgeführt, bevor die Response an den Client gesendet wird.

  }

  /**
   * A function from an input to a result.
   *
   * @param <T> the type of the input to the function
   * @param <U> the type of the result of the function
   */
  public interface ClosingFunction<T extends @Nullable Object, U extends @Nullable Object> {

    /**
     * Applies this function to an input, or throws an exception if unable to do so.
     *

///

### Paso 4: define la **path operation function** { #step-4-define-the-path-operation-function }

Esta es nuestra "**path operation function**":

* **path**: es `/`.
* **operation**: es `get`.
* **function**: es la función debajo del "decorador" (debajo de `@app.get("/")`).

{* ../../docs_src/first_steps/tutorial001_py39.py hl[7] *}

Esta es una función de Python.

1. Esta es la función generadora. Es una "función generadora" porque contiene declaraciones `yield` dentro.
2. Al usar un bloque `with`, nos aseguramos de que el objeto similar a un archivo se cierre después de que la función generadora termine. Así, después de que termina de enviar el response.

In some cases you don't really need the return value of a dependency inside your *path operation function*.

Or the dependency doesn't return a value.

But you still need it to be executed/solved.

For those cases, instead of declaring a *path operation function* parameter with `Depends`, you can add a `list` of `dependencies` to the *path operation decorator*.

          V,
          I extends Table<R, C, V>>
      Collector<T, ?, I> toTable(
          java.util.function.Function<? super T, ? extends R> rowFunction,
          java.util.function.Function<? super T, ? extends C> columnFunction,
          java.util.function.Function<? super T, ? extends V> valueFunction,
          java.util.function.Supplier<I> tableSupplier) {
    return TableCollectors.<T, R, C, V, I>toTable(

    EquivalenceTester.of(Equivalence.equals().onResultOf(Functions.toStringFunction()))
        .addEquivalenceGroup(new IntValue(1), new IntValue(1))
        .addEquivalenceGroup(new IntValue(2))
        .test();
  }

  public void testOnResultOf_equals() {
    new EqualsTester()
        .addEqualityGroup(
            Equivalence.identity().onResultOf(Functions.toStringFunction()),