```

The last `CommonQueryParams`, in:

```Python
... Depends(CommonQueryParams)
```

...is what **FastAPI** will actually use to know what is the dependency.

From it is that FastAPI will extract the declared parameters and that is what FastAPI will actually call.

---

In this case, the first `CommonQueryParams`, in:

=== "Python 3.8+"

    ```Python

  validations:
    required: true
- type: textarea
  attributes:
    label: Description
    description: What do these counters measure?
  validations:
    required: true
- type: textarea
  attributes:
    label: Rationale
    description: |
      Why is the counter important?
      For example, what new insights will it provide, and how will that information be used?

// errLessData - returned when less data available than what was requested.
var errLessData = StorageErr("less data available than what was requested")

// errMoreData = returned when more data was sent by the caller than what it was supposed to.
var errMoreData = StorageErr("more data was sent than what was advertised")

// indicates readDirFn to return without further applying the fn()

 * #iterator()} method after the first, and whose iterator is always unmodifiable.
 *
 * <p>The {@code Iterable} specification does not make it absolutely clear what should happen on a
 * second invocation, so implementors have made various choices, including:
 *
 * <ul>
 *   <li>returning the same iterator again
 *   <li>throwing an exception of some kind

In this case, you could want to document how that external API *should* look like. What *path operation* it should have, what body it should expect, what response it should return, etc.

## An app with callbacks

Let's see all this with an example.

Imagine you develop an app that allows creating invoices.

labels: ["pkgsite/package-removal"]
body:
  - type: markdown
    attributes:
      value: "Please answer these questions before submitting your issue. Thanks!"
  - type: input
    id: package-path
    attributes:
      label: "What is the path of the package that you would like to have removed?"
      description: |
        We can remove packages with a shared path prefix.

* <a href="https://www.linkedin.com/in/tiangolo/" class="external-link" target="_blank">Follow me on **LinkedIn**</a>.
    * Hear when I make announcements or release new tools (although I use Twitter more often 🤷‍♂).
* Read what I write (or follow me) on <a href="https://dev.to/tiangolo" class="external-link" target="_blank">**Dev.to**</a> or <a href="https://medium.com/@tiangolo" class="external-link" target="_blank">**Medium**</a>.

For any non-trivial change, we need to be able to answer these questions:

* Why is this change done? What's the use case?
* For user facing features, what will the API look like?
* What test cases should it have? What could go wrong?
* How will it roughly be implemented? We'll happily provide code pointers to save you time.

 * #iterator()} method after the first, and whose iterator is always unmodifiable.
 *
 * <p>The {@code Iterable} specification does not make it absolutely clear what should happen on a
 * second invocation, so implementors have made various choices, including:
 *
 * <ul>
 *   <li>returning the same iterator again
 *   <li>throwing an exception of some kind

			for _, sz := range test.sizes {
				h.add(sz)
			}
			got := h.toMap()
			exp := test.want
			// what is in exp is in got
			for k := range exp {
				if exp[k] != got[k] {
					t.Fatalf("interval %s: Expected %d values but got %d values\n", k, exp[k], got[k])
				}
			}
			// what is absent in exp is absent in got too
			for k := range got {
				if _, ok := exp[k]; !ok && got[k] > 0 {