public static CloudName from(String cloud) {
        return switch (cloud) {
            case "aws" -> AWS;
            case "azure" -> AZURE;
            case "gcp" -> GCP;
            case "default" -> DEFAULT;
            case "yahoo" -> YAHOO;
            default -> new CloudName(cloud);
        };
    }
@Test
    void returns_same_instance_for_known_clouds() {
        assertSame(CloudName.from("aws"), CloudName.AWS);
        assertSame(CloudName.from("azure"), CloudName.AZURE);
        assertSame(CloudName.from("gcp"), CloudName.GCP);
        assertSame(CloudName.from("default"), CloudName.DEFAULT);
        assertSame(CloudName.from("yahoo"), CloudName.YAHOO);
        assertThrows(IllegalArgumentException.class, () -> CloudName.from("aWs")); // Must be lowercase
    }