class ExecutablePluginBase

abstract class ExecutablePluginBase extends ContextAwarePluginBase implements ExecutableInterface {
    
    /**
     * Gets an array of definitions of available configuration options.
     *
     * @todo: This needs to go into an interface.
     *
     * @return \Drupal\Core\TypedData\DataDefinitionInterface[]
     *   An array of typed data definitions describing available configuration
     *   options, keyed by option name.
     */
    public function getConfigDefinitions() {
        $definition = $this->getPluginDefinition();
        if (!empty($definition['configuration'])) {
            return $definition['configuration'];
        }
        return [];
    }
    
    /**
     * Gets the definition of a configuration option.
     *
     * @param string $key
     *   The key of the configuration option to get.
     *
     * @todo: This needs to go into an interface.
     *
     * @return \Drupal\Core\TypedData\DataDefinitionInterface|false
     *   The typed data definition describing the configuration option, or FALSE
     *   if the option does not exist.
     */
    public function getConfigDefinition($key) {
        $definition = $this->getPluginDefinition();
        if (!empty($definition['configuration'][$key])) {
            return $definition['configuration'][$key];
        }
        return FALSE;
    }
    
    /**
     * Gets all configuration values.
     *
     * @todo: This needs to go into an interface.
     *
     * @return array
     *   The array of all configuration values, keyed by configuration option
     *   name.
     */
    public function getConfig() {
        return $this->configuration;
    }
    
    /**
     * Sets the value of a particular configuration option.
     *
     * @param string $key
     *   The key of the configuration option to set.
     * @param mixed $value
     *   The value to set.
     *
     * @todo This doesn't belong here. Move this into a new base class in
     *   https://www.drupal.org/node/1764380.
     * @todo This does not set a value in \Drupal::config(), so the name is confusing.
     *
     * @return $this
     *   The executable object for chaining.
     *
     * @throws \Drupal\Component\Plugin\Exception\PluginException
     *   If the provided configuration value does not pass validation.
     */
    public function setConfig($key, $value) {
        if ($definition = $this->getConfigDefinition($key)) {
            $typed_data = \Drupal::typedDataManager()->create($definition, $value);
            if ($typed_data->validate()
                ->count() > 0) {
                throw new PluginException("The provided configuration value does not pass validation.");
            }
        }
        $this->configuration[$key] = $value;
        return $this;
    }

}