Sets the value for a defined context.
string $name: The name of the context in the plugin definition.
mixed $value: The value to set the context to. The value has to validate against the provided context definition.
\Drupal\Component\Plugin\ContextAwarePluginInterface. A context aware plugin object for chaining.
\Drupal\Component\Plugin\Exception\PluginException If the value does not pass validation.
public function setContextValue($name, $value);