src/Camunda/Service/TaskService.php
public function claim($id, $userId)
    {
        $resource = str_replace('{id}', $id, static::RESOURCE_CLAIM);
        $options = [
            'headers' => [
                'Accept' => 'application/json',
                'Content-Type' => 'application/json'
            ],
            'json' => [
                'userId' => $userId
            ]
        ];
        $this->execute('POST', $resource, $options);
    }
public function claim($id, $userId)
    {
        $resource = str_replace('{id}', $id, static::RESOURCE_CLAIM);
        $options = [
            'headers' => [
                'Accept' => 'application/json',
                'Content-Type' => 'application/json'
            ],
            'json' => [
                'userId' => $userId
            ]
        ];
        $this->execute('POST', $resource, $options);
    }
Claim task

@param string $id
@param string $userId