private void addPattern(Entity a,Entity b,List<PatternExtract> patterns){
  if (a.getEnd() < b.getBegin()) {
    patterns.add(new PatternExtract(a,b,a.getEnd(),b.getBegin()));
  }
 else   if (a.getBegin() > b.getEnd()) {
    patterns.add(new PatternExtract(b,a,b.getEnd(),a.getBegin()));
  }
 else {
  }
}

private void addPattern ( Entity a , Entity b , List < PatternExtract > patterns ) { if ( a . getEnd ( ) < b . getBegin ( ) ) { patterns . add ( new PatternExtract ( a , b , a . getEnd ( ) , b . getBegin ( ) ) ) ; } else if ( a . getBegin ( ) > b . getEnd ( ) ) { patterns . add ( new PatternExtract ( b , a , b . getEnd ( ) , a . getBegin ( ) ) ) ; } else { } }
create and add the pattern , or do nothing if the entities overlap
