default InputStream getInputStream() {
		try {
			return Files.newInputStream(getFile());
		} catch (IOException e) {
			throw new ResourceNotFoundException(getOriginalResource(), "Could not open input stream for resource", e);
		}
	}
Retrieves an InputStream for the resource represented by this reference. If a
file representation of the resource exists, the InputStream is opened for
that file. If no file is associated, this method returns null.

@return an InputStream for the resource, or null if no file is associated
src/main/java/dev/jbang/source/ResourceRef.java