code: public static void setChemCompProvider(ChemCompProvider provider) {
  		logger.debug("Setting new chem comp provider to "+provider.getClass().getCanonicalName());
  		chemCompProvider = provider;
  		// clear cache
  		cache.clear();
  	}
docs: The new ChemCompProvider will be set in the static variable,
  so this provider will be used from now on until it is changed
  again. Note that this change can have unexpected behavior of
  code executed afterwards.
  <p>
  Changing the provider also resets the cache, so any groups
  previously accessed will be reread or re-downloaded.
  
  @param provider