default @SideEffectFree boolean isValidLong(final @NonNull LongRange range) {
        return this.isValidLong(range.minLong(), range.maxLong());
    }
Returns whether {@link #peekString()} contain a valid {@link Long}
within the given range.

@param range range of accepted numbers
@return whether the input until the next whitespace contains a valid {@link Long}
cloud-core/src/main/java/org/incendo/cloud/context/CommandInput.java