public Long getNumber(String key) {
		String val = get(key);
		if (key != null) {
			try {
				return Long.parseLong(val);
			} catch (NumberFormatException ex) {
				// Ignore
			}
		}
		return null;
	}
Returns the given value from this Configuration or its fallback

@param key          The key of the value to return
@param defaultValue The value to return if the key wasn't found
@return The associated value if it was found or `defaultValue` if not
src/main/java/dev/jbang/Configuration.java