[1.13.2] Change config values at runtime

public class Config {
	public static final ForgeConfigSpec CLIENT_SPEC;
	public static final ClientConfig CLIENT;

	static {
		Pair<ClientConfig, ForgeConfigSpec> pair = new ForgeConfigSpec.Builder().configure(ClientConfig::new);
		CLIENT_SPEC = pair.getRight();
		CLIENT = pair.getLeft();
	}

	public static class ClientConfig {
		private final BooleanValue example;

		public ClientConfig(ForgeConfigSpec.Builder builder) {
			this.example = builder
					.comment("Example comment")
					.translation("Example translation")
					.define("example_value", false);
		}

		public boolean isExample() {
			return this.example.get();
		}
	}
}