DrupalOAuthClient::signatureMethod defaults to SHA1, not SHA512

In DrupalOAuthClient, line 44 (in 7.x-3.x-dev), we see the following param descriptor in the docblock:

  /* @param string $method
   *  Optional. The hmac hashing algorithm to use. Defaults to 'sha512' which
   *  has superseded sha1 as the recommended alternative.
   */

but in the actual function signature, we see this:

public static function signatureMethod($method = 'SHA1', $fallback_to_sha1 = TRUE) {

Since SHA1 is considered insecure, should the value of $method not be set to 'SHA512'?