code: public static Set<String> findPrefixesForExportedVariables( Instance instance ) {
  
  		Set<String> result = new HashSet<> ();
  		for( String exportedVariableName : InstanceHelpers.findAllExportedVariables( instance ).keySet())
  			result.add( VariableHelpers.parseVariableName( exportedVariableName ).getKey());
  
  		return result;
  	}
docs: Finds the component and facet names that prefix the variables an instance exports.
  @param instance an instance
  @return a non-null set with all the component and facet names this instance exports