code: function calculateSubscriptionWeight( eventName ) {
     const parts = eventName.split( TOPIC_SEPARATOR );
     const weight = [ 0, 0 ];
     parts.forEach( part => {
        if( part.length > 0 ) {
           weight[ 0 ]++;
           weight[ 1 ] += part.split( SUB_TOPIC_SEPARATOR ).length - 1;
        }
     } );
     return weight;
  }
docs: ////////////////////////////////////////////////////////////////////////////////////////////////////////////