azure-storage-common/src/Common/Internal/ServiceSettings.php
protected static function setting($name)
    {
        $validValues = func_get_args();

        // Remove $name argument.
        unset($validValues[0]);

        $validValuesCount = func_num_args();

        $predicate = function ($settingValue) use ($validValuesCount, $validValues) {
            if (empty($validValues)) {
                // No restrictions, succeed,
                return true;
            }

            // Check to find if the $settingValue is valid or not. The index must
            // start from 1 as unset deletes the value but does not update the array
            // indecies.
            for ($index = 1; $index < $validValuesCount; $index++) {
                if ($settingValue == $validValues[$index]) {
                    // $settingValue is found in valid values set, succeed.
                    return true;
                }
            }

            throw new \RuntimeException(
                sprintf(
                    Resources::INVALID_CONFIG_VALUE,
                    $settingValue,
                    implode("\n", $validValues)
                )
            );

            // $settingValue is missing in valid values set, fail.
            return false;
        };

        return self::settingWithFunc($name, $predicate);
    }
protected static function setting($name)
    {
        $validValues = func_get_args();

        // Remove $name argument.
        unset($validValues[0]);

        $validValuesCount = func_num_args();

        $predicate = function ($settingValue) use ($validValuesCount, $validValues) {
            if (empty($validValues)) {
                // No restrictions, succeed,
                return true;
            }

            // Check to find if the $settingValue is valid or not. The index must
            // start from 1 as unset deletes the value but does not update the array
            // indecies.
            for ($index = 1; $index < $validValuesCount; $index++) {
                if ($settingValue == $validValues[$index]) {
                    // $settingValue is found in valid values set, succeed.
                    return true;
                }
            }

            throw new \RuntimeException(
                sprintf(
                    Resources::INVALID_CONFIG_VALUE,
                    $settingValue,
                    implode("\n", $validValues)
                )
            );

            // $settingValue is missing in valid values set, fail.
            return false;
        };

        return self::settingWithFunc($name, $predicate);
    }
Creates a setting value condition that validates it is one of the
passed valid values.

@param string $name The setting key name.

@return array