code: public function setOutgoingContext($context)
      {
          if (is_string($context)) {
              $outgoingContext = new Context($context);
          } elseif (is_array($context)) {
              if (! isset($context['name'])) {
                  throw new RuntimeException('Context must have a name');
              }
  
              $name = $context['name'];
  
              $lifespan = 1;
              if (isset($context['lifespan'])) {
                  $lifespan = is_numeric($context['lifespan']) ? $context['lifespan'] : null;
              }
  
              $parameters = [];
              if (isset($context['parameters'])) {
                  $parameters = is_array($context['parameters']) ? $context['parameters'] : null;
              }
  
              $outgoingContext = new Context($name, $lifespan, $parameters);
          } elseif ($context instanceof Context) {
              $outgoingContext = $context;
          } else {
              throw new RuntimeException('Context must be provided');
          }
  
          $this->outgoingContexts[] = $outgoingContext;
  
          return $this;
      }
docs: Set a new Dialogflow outgoing context.
  Reference: https://dialogflow.com/docs/contexts.
  
  @param string|array|\Dialogflow\Context $context
  
  @return \Dialogflow\WebhookClient