It might be useful, for example, to return custom headers or cookies.

## Return a `Response`

In fact, you can return any `Response` or any sub-class of it.

!!! tip
    `JSONResponse` itself is a sub-class of `Response`.

And when you return a `Response`, **FastAPI** will pass it directly.

It won't do any data conversion with Pydantic models, it won't convert the contents to any type, etc.

            .filter { "UNKNOWN" != it.key }
            .filter { model.subprojects.getSubprojectByName(it.key) != null }
            .map { SubprojectTestClassTime(model.subprojects.getSubprojectByName(it.key)!!, it.value.filter { it.testClassAndSourceSet.sourceSet != "test" }) }
            .sortedBy { -it.totalTime }
            .filter { onlyNativeSubprojectsForIntelMacs(testCoverage, it.subProject.name) }

                        os to (testProject to performanceTestDuration)
                    }
            }
        }
        return pairs.groupBy({ it.first }, { it.second })
            .mapValues { entry -> entry.value.groupBy({ it.first }, { it.second }) }
    }

    private
    fun readPerformanceTestConfigurations(performanceTestsCiJson: File): List<PerformanceTestConfiguration> {

        allTestedVersions = testedVersions.map { VersionNumber.parse(it.gradleVersion().version) }
            .groupBy { "${it.major}.${it.minor}" }
            .map { (_, v) -> v.maxOrNull()!!.format() }

        // Limit to first and last release of each major version
        mainTestedVersions = testedVersions.map { VersionNumber.parse(it.gradleVersion().version) }
            .groupBy { it.major }

        reports.filter { it.isDirectory }.forEach {
            val destFile = rootBuildDir.resolve("report$projectPathName-${it.name}.zip")
            zip(destFile, it)
        }

        // Zip all files in project build directory into a single zip file to avoid publishing too many tiny files
        reports.filter { it.isFile && it.toPath().startsWith(projectBuildDirPath) }

But all this functionality of using asynchronous code with `async` and `await` is many times summarized as using "coroutines". It is comparable to the main key feature of Go, the "Goroutines".

## Conclusion

                    it as KtPsiDiagnosticWithParameters2<*, *>,
                    token,
                    convertArgument(it.a, this),
                    convertArgument(it.b, this)
                )
            }
            is KtDiagnosticFactory3<*, *, *> -> KtFirDiagnostic3Creator<Any?, Any?, Any?> {
                KtCompilerPluginDiagnostic3Impl(
                    it as KtPsiDiagnosticWithParameters3<*, *, *>,

* **FastAPI**:
    * The same way that Starlette uses Uvicorn and cannot be faster than it, **FastAPI** uses Starlette, so it cannot be faster than it.

    this?.takeIf { it.isNotEmpty() }
        ?.joinToString(separator = ", ", prefix = "<", postfix = ">", transform = transform)
        ?: ""


private
val ApiTypeUsage.isGroovyNamedArgumentMap
    get() = isMap && (
        typeArguments.all { it.isAny }
            || typeArguments.all { it.isStarProjectionTypeUsage }

    You could have custom internal logic to separate it by colon caracters (`:`) or
    similar, and get the two parts `items` and `read`. Many applications do that to
    group and organize permissions, you could do it as well in your application, just
    know that that it is application specific, it's not part of the specification.


    grant_type: the OAuth2 spec says it is required and MUST be the fixed string "password".