lib/Tumblr/API/Client.php
public function setConsumer($consumerKey, $consumerSecret)
    {
        $this->apiKey = $consumerKey;
        $this->requestHandler->setConsumer($consumerKey, $consumerSecret);
    }
public function setConsumer($consumerKey, $consumerSecret)
    {
        $this->apiKey = $consumerKey;
        $this->requestHandler->setConsumer($consumerKey, $consumerSecret);
    }
Set the consumer for this client

@param string $consumerKey    the consumer key
@param string $consumerSecret the consumer secret