Set the clientOptions.
Options from presets are merging with the client options.

@return void
191634
protected function loadOptions(): void
    {
        $options = [];

        if ($this->preset == 'custom') {
            $optionsFile = null;
        } else {
            $optionsFile = __DIR__ . '/presets/' . $this->preset . '.php';
        }

        if ($optionsFile !== null) {
            if (!is_file($optionsFile)) {
                throw new InvalidConfigException('The CKEditor options file can not be loaded.');
            }
            $options = require($optionsFile);
        }

        $this->clientOptions = ArrayHelper::merge(
            $options,
            $this->clientOptions
        );
    }
950691
private static function setClient()
    {
        if (self::$client === null) {
            self::$client = new Client([
                'base_uri'  => self::$environment,
                'timeout'   => self::TIMEOUT,
                'verify'    => self::VERIFY,
            ]);
        }
    }
841276
private function setDefaultOptions()
    {
        // The default configuration settings.
        $this->di()->getConfig()->setOptions([
            'core.version'                      => $this->getVersion(),
            'core.language'                     => 'en',
            'core.encoding'                     => 'utf-8',
            'core.decode_utf8'                  => false,
            'core.prefix.function'              => 'jaxon_',
            'core.prefix.class'                 => 'Jaxon',
            // 'core.request.uri'               => '',
            'core.request.mode'                 => 'asynchronous',
            'core.request.method'               => 'POST',    // W3C: Method is case sensitive
            'core.response.merge.ap'            => true,
            'core.response.merge.js'            => true,
            'core.debug.on'                     => false,
            'core.debug.verbose'                => false,
            'core.process.exit'                 => true,
            'core.process.clean'                => false,
            'core.process.timeout'              => 6000,
            'core.error.handle'                 => false,
            'core.error.log_file'               => '',
            'core.jquery.no_conflict'           => false,
            'js.lib.output_id'                  => 0,
            'js.lib.queue_size'                 => 0,
            'js.lib.load_timeout'               => 2000,
            'js.lib.show_status'                => false,
            'js.lib.show_cursor'                => true,
            'js.app.dir'                        => '',
            'js.app.minify'                     => true,
            'js.app.options'                    => '',
        ]);
    }
314926
protected function _setOptions()
    {
        if (!is_null($this->getHeader())) {
            $this->_setOpt(CURLOPT_HTTPHEADER, $this->getHeader());
        }
        $this->_setOpt(CURLOPT_URL, $this->getUrl());

        if ($this->getMethod() == "POST") {
            $this->_setOpt(CURLOPT_POST, 1);
            $this->_setOpt(CURLOPT_POSTFIELDS, $this->_formParamsForPost($this->getParameters()));
        }

        $aOptions = $this->getOptions();
        if (count($aOptions)) {
            foreach ($aOptions as $sName => $mValue) {
                $this->_setOpt(constant($sName), $mValue);
            }
        }
    }
1025974
protected function configure(array $options): void
    {
        $options = array_merge([
            'socket_class' => ClientSocket::class,
            'on_data_callback' => null,
            'socket_options' => [],
        ], $options);

        parent::configure($options);
    }
1047324
public function setDefaultOptions()
    {
        $this->options = array(
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_HEADER         => false,
            CURLOPT_ENCODING       => 'gzip,deflate',
            CURLOPT_AUTOREFERER    => true,
            CURLOPT_CONNECTTIMEOUT => 15,
            CURLOPT_TIMEOUT        => 30,
        );
    }
615453
protected function setDefaultOptions(array $options = [])
    {
        $this->options = $this->formHelper->mergeOptions($this->allDefaults(), $this->getDefaults());
        $this->options = $this->prepareOptions($options);

        $defaults = $this->setDefaultClasses($options);
        $this->options = $this->formHelper->mergeOptions($this->options, $defaults);

        $this->setupLabel();
    }
710716
public function setOptions(array $options)
    {
        foreach ($options as $name => $value) {
            $this->setOption($name, $value);
        }
    }
1356018
public function setOptions(array $options = null): void
    {
        // store options by default
        $this->options = (array)$options;

        // apply options
        foreach ($this->options as $key => $value) {
            $this->setOption($key, $value);
        }
    }
258328
protected function resolveClient()
    {
        if (!isset($this->client)) {
            $this->setClient(call_user_func(static::$clientResolver, $this->getOptions()));
        }
    }
602668
protected function set_preset() {

		// Set preset from the choices.
		$this->preset = $this->choices;

		// We're using a flat select.
		foreach ( $this->choices as $key => $args ) {
			$this->choices[ $key ] = $args['label'];
		}
	}
102055
function setOptions( options ) {
		if ( !options.hasOwnProperty( 'objectMode' ) ) {
			options.objectMode = false;
		}
		if ( !options.hasOwnProperty( 'encoding' ) ) {
			options.encoding = null;
		}
	}
472708
public function setOptions(array $options)
    {
        foreach ($options as $k => $v) {
            $this->setOption($k, $v);
        }
    }
1123532
private function __setCurlOptions($curl, array $options)
    {
        foreach ($options as $option => $value)
        {
            if (false !== curl_setopt($curl, $option, $value))
            {
                continue;
            }
            throw new ClientException(
                sprintf('Failed setting CURL option %d to %s', $option, var_export($value, true))
            );
        }
    }
365814
private function setRequestOptions(array $options)
    {
        $config = $this->getGuzzleClient()->getConfig();
        $config->set(Client::REQUEST_OPTIONS, $options);

        $this->getGuzzleClient()->setConfig($config);
    }
832111
public function setOptions(RectangleOptions $rectangleOptions)
    {
        $options = array_filter($rectangleOptions->options);
        $this->options = ArrayHelper::merge($this->options, $options);
    }
1094038
protected function setupDefaultOptions()
    {
        $defaultOptions = [
            'overwriteInitial' => false,
            'initialPreviewAsData' => true,
            'browseLabel' => trans('admin.browse'),
            'showRemove' => false,
            'showUpload' => false,
//            'initialCaption'       => $this->initialCaption($this->value),
            'deleteExtraData' => [
                $this->formatName($this->column) => static::FILE_DELETE_FLAG,
                static::FILE_DELETE_FLAG => '',
                '_token' => csrf_token(),
                '_method' => 'PUT',
            ],
        ];

        if ($this->form instanceof Form) {
            $defaultOptions['deleteUrl'] = $this->form->resource().'/'.$this->form->model()->getKey();
        }

        $this->options($defaultOptions);
    }