function editOnCompositionStart(
  editor: DraftEditor,
  e: SyntheticEvent<>,
): void {
  editor.setMode('composite');
  editor.update(
    EditorState.set(editor._latestEditorState, {inCompositionMode: true}),
  );
  // Allow composition handler to interpret the compositionstart event
  editor._onCompositionStart(e);
}
The user has begun using an IME input system. Switching to `composite` mode
allows handling composition input and disables other edit behavior.