WC_API_Authentication::urlencode_rfc3986()
Method: Encodes a value according to RFC 3986. Supports multidimensional arrays.
Source: includes/legacy/api/v3/class-wc-api-authentication.php:309
WC_API_Authentication::exit_with_unauthorized_headers()
Method: If the consumer_key and consumer_secret $_GET parameters are NOT provided and the Basic auth headers are either not present or the consumer secret does not match the consumer key provided, then return the correct Basic headers and an error message.
Source: includes/legacy/api/v3/class-wc-api-authentication.php:109