Ensures a payload string is represented as a Data URI.
Existing Data URIs are preserved; raw base64 payloads receive a best-effort prefix using the supplied MIME type.
Raw base64 payload or existing Data URI.
MIME type used when wrapping raw base64 data.
Proper Data URI string.
Ensures a payload string is represented as a Data URI.
Existing Data URIs are preserved; raw base64 payloads receive a best-effort prefix using the supplied MIME type.