Retrieve the current HTTP Basic Auth credentials used by this service. Every
SWMLService instance has auth credentials — either
explicitly provided in the constructor, read from environment variables, or
auto-generated at startup.
When true, returns a 3-tuple that includes the credential source as the
third element. The source is one of:
"provided" — credentials were passed through constructor options"environment" — credentials came from SWML_BASIC_AUTH_USER and SWML_BASIC_AUTH_PASSWORD environment variables"auto-generated" — credentials were randomly generated at startup[string, string] — A [username, password] tuple when includeSource is
false or omitted.
[string, string, 'provided' | 'environment' | 'auto-generated'] — A
[username, password, source] tuple when includeSource is true.