protected String addSyntaxHighlight(String html) {
		StringBuilder stringBuilder = new StringBuilder();
		stringBuilder.append("syntaxHighlight: {");
		if (swaggerUiConfig.getSyntaxHighlight().getActivated() != null) {
			stringBuilder.append("activated: ");
			stringBuilder.append(swaggerUiConfig.getSyntaxHighlight().getActivated());
		}
		if (StringUtils.isNotEmpty(swaggerUiConfig.getSyntaxHighlight().getTheme())) {
			if (swaggerUiConfig.getSyntaxHighlight().getActivated() != null)
				stringBuilder.append(" , ");
			stringBuilder.append("theme: \"");
			stringBuilder.append(swaggerUiConfig.getSyntaxHighlight().getTheme());
			stringBuilder.append("\"");
		}
		stringBuilder.append("},\n");
		stringBuilder.append(PRESETS);
		return html.replace(PRESETS, stringBuilder.toString());
	}
Add syntax highlight string.

@param html the html
@return the string
springdoc-openapi-starter-common/src/main/java/org/springdoc/ui/AbstractSwaggerIndexTransformer.java