Returns info coming from the transport layer.
This method SHOULD NOT throw any ExceptionInterface and SHOULD be non-blocking.
The returned info is "live": it can be empty and can change from one call to
another, as the request/response progresses.
The following info MUST be returned:
- canceled (bool) - true if the response was canceled using ResponseInterface::cancel(), false otherwise
- error (string|null) - the error message when the transfer was aborted, null otherwise
- http_code (int) - the last response code or 0 when it is not known yet
- http_method (string) - the HTTP verb of the last request
- redirect_count (int) - the number of redirects followed while executing the request
- redirect_url (string|null) - the resolved location of redirect responses, null otherwise
- response_headers (array) - an array modelled after the special $http_response_header variable
- start_time (float) - the time when the request was sent or 0.0 when it's pending
- url (string) - the last effective URL of the request
- user_data (mixed) - the value of the "user_data" request option, null if not set
When the "capture_peer_cert_chain" option is true, the "peer_certificate_chain"
attribute SHOULD list the peer certificates as an array of OpenSSL X.509 resources.
Other info SHOULD be named after curl_getinfo()'s associative return value.
An array of all available info, or one of them when $type is
provided, or null when an unsupported type is requested