src/Riak/Api/Http.php
public function responseHeaderCallback($ch, $header)
    {
        if (strpos($header, ':')) {
            list ($key, $value) = explode(':', $header, 2);

            $value = trim($value);

            if (!empty($value)) {
                if (!isset($this->responseHeaders[$key])) {
                    $this->responseHeaders[$key] = $value;
                } elseif (is_array($this->responseHeaders[$key])) {
                    $this->responseHeaders[$key] = array_merge($this->responseHeaders[$key], [$value]);
                } else {
                    $this->responseHeaders[$key] = array_merge([$this->responseHeaders[$key]], [$value]);
                }
            }
        }

        return strlen($header);
    }
public function responseHeaderCallback($ch, $header)
    {
        if (strpos($header, ':')) {
            list ($key, $value) = explode(':', $header, 2);

            $value = trim($value);

            if (!empty($value)) {
                if (!isset($this->responseHeaders[$key])) {
                    $this->responseHeaders[$key] = $value;
                } elseif (is_array($this->responseHeaders[$key])) {
                    $this->responseHeaders[$key] = array_merge($this->responseHeaders[$key], [$value]);
                } else {
                    $this->responseHeaders[$key] = array_merge([$this->responseHeaders[$key]], [$value]);
                }
            }
        }

        return strlen($header);
    }
Response header callback

Handles callback from curl when the response is received, it parses the headers into an array sets them as
member of the class.

Has to be public for curl to be able to access it.

@param $ch
@param $header

@return int