src/vs/editor/contrib/parameterHints/browser/parameterHintsModel.ts/ParameterHintsModel/onModelChanged
class ParameterHintsModel:	private onModelChanged(): void {
		this.cancel();

		this.triggerChars.clear();
		this.retriggerChars.clear();

		const model = this.editor.getModel();
		if (!model) {
			return;
		}

		for (const support of this.providers.ordered(model)) {
			for (const ch of support.signatureHelpTriggerCharacters || []) {
				if (ch.length) {
					const charCode = ch.charCodeAt(0);
					this.triggerChars.add(charCode);

					// All trigger characters are also considered retrigger characters
					this.retriggerChars.add(charCode);
				}
			}

			for (const ch of support.signatureHelpRetriggerCharacters || []) {
				if (ch.length) {
					this.retriggerChars.add(ch.charCodeAt(0));
				}
			}
		}
	}