predictionText property
Text to display at the cursor, supplied by the caller, drawn underlined in the same style as IME composing text.
This is purely a rendering hook: the text is never written into the terminal buffer, so it has no effect on the terminal's state or on what the host process sees. It exists for callers that predict input locally (for example to keep a high-latency connection feeling responsive) and want to show that guess at the cursor until it is confirmed or discarded, without risking a stale prediction ever becoming permanent screen content.
Suppressed while IME composition is active, since the two would otherwise be drawn in the same place.
Implementation
final String? predictionText;