public static <T> void doIfNull(final T input,
                                    final CheckedConsumer<T> trueFunction) {
        doIfNull(input, trueFunction, t -> {
        });
    }
Do if null.

@param <T>          the type parameter
@param input        the input
@param trueFunction the true function
core/cas-server-core-util-api/src/main/java/org/apereo/cas/util/function/FunctionUtils.java