# WebSockets

When defining WebSockets, you normally declare a parameter of type `WebSocket` and with it you can read data from the client and send data to it.

It is provided directly by Starlette, but you can import it from `fastapi`:

```python
from fastapi import WebSocket
```

/// tip

// This file is part of MinIO Object Storage stack
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of

    private boolean foundAndRemovedExactReference(Iterable<E> elements, E target) {
      for (Iterator<E> it = elements.iterator(); it.hasNext(); ) {
        E element = it.next();
        if (element == target) {
          it.remove();
          return true;
        }
      }
      return false;
    }

}

private fun Char.charCode() =
  code.toString(16).let {
    if (it.length < 2) {
      "0$it"
    } else {
      it
    }
  }

internal fun commonHeadersOf(vararg inputNamesAndValues: String): Headers {
  require(inputNamesAndValues.size % 2 == 0) { "Expected alternating header names and values" }

  // Make a defensive copy and clean it up.
  val namesAndValues: Array<String> = arrayOf(*inputNamesAndValues)

//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of

        is EnumDeclaration -> tryResolve({ it.resolve().qualifiedName }) { inferClassName(unit) }
        is ClassOrInterfaceDeclaration -> tryResolve({ it.resolve().qualifiedName }) { inferClassName(unit) }
        is MethodDeclaration -> tryResolve({ it.resolve().qualifiedSignature }) { "${inferClassName(unit)}.${it.name}()" }
        is AnnotationDeclaration -> tryResolve({ it.resolve().qualifiedName }) { "${inferClassName(unit)}.${it.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> {

      Iterable<? extends T> iterable, Comparator<T> comparator) {
    checkNotNull(comparator);
    Iterator<? extends T> it = iterable.iterator();
    if (it.hasNext()) {
      T prev = it.next();
      while (it.hasNext()) {
        T next = it.next();
        if (comparator.compare(prev, next) >= 0) {
          return false;
        }
        prev = next;
      }
    }

**FastAPI** will create the object of type `BackgroundTasks` for you and pass it as that parameter.

## Create a task function { #create-a-task-function }

Create a function to be run as the background task.

It is just a standard function that can receive parameters.

It can be an `async def` or normal `def` function, **FastAPI** will know how to handle it correctly.

    fun groovyImports(): String {
        val imports: List<String> =
            generateImportPackages()
                .map { "$it.*" } + "" +
                AnnotationGenerator.ADDITIONAL_DEFAULT_IMPORTS
        return imports.joinToString(separator = "\n") {
            if (it.isBlank()) "" else "import $it"
        }
    }

    private
    inline fun <reified Receiver> groovyReceiverAccessors(): String {