public final static void evaluateStats() {
        logger.info( "[ " + System.currentTimeMillis() + " ] evaluating stats on " + stats.name + " ..." ) ;
        sentenceMap.entrySet().stream().parallel().map((entry) -> entry.getValue()).forEach((s) -> {
            final int _tokenCount = s.tokens.length;
            stats.wordCount += _tokenCount;
            
            for( int i = 0; i < _tokenCount; i++ )  {
                final String TAG = s.tags[ i ].toUpperCase();
                if( TAG.equals( Tags.NOUN_SINGULAR ) || TAG.equals( Tags.NOUN_PLURAL  ) ) {
                    Noun _n = new Noun( s.tokens[ i ].toLowerCase()  ) ;
                    long _freq = stats.add( _n );
                }
                else if( TAG.equals( Tags.VERB_BASE_FORM ) || TAG.equals( Tags.VERB_GERUND ) || TAG.equals( Tags.VERB_PAST_PARTICIPLE ) || TAG.equals( Tags.VERB_PAST_TENSE ) || TAG.equals( Tags.VERB_PRESENT_TENSE)  || TAG.equals( Tags.VERB_PRESENT_TENSE_3RD_SINGULAR ) )   {
                    Verb _v = new Verb( s.tokens[ i ].toLowerCase() );
                    long _freq = stats.add( _v );
                }
            }
        });
        logger.info( "[ " + System.currentTimeMillis() + " ] done evaluating stats" );
    }