code: @Override
  	public OutputStream store(String resource) {
  		if(Strings.isValid(resource)) {
  			resources.add(resource);
  			return new NullOutputStream();
  		}
  		return null;
  	}
docs: This method actually does nothing to store the binary data, it returns a
  void outputStream and there is no use in writing anything to it; as a side
  effect, it records the name of the resource so that it <em>looks like</em>
  the resource is actually stored, but it is not: it will be retrieved from
  the remote server when requested.
  
  @see org.dihedron.patterns.cache.Storage#store(java.lang.String)