default int readInteger(final int radix) {
        return Integer.parseInt(this.readString(), radix);
    }
Reads the {@link #readString() string until the next whitespace} and parses
in into a {@link Integer}.

@param radix radix
@return the parsed integer
@throws NumberFormatException If the string cannot be parsed into a {@link Integer}.
cloud-core/src/main/java/org/incendo/cloud/context/CommandInput.java