docs: public void plus(ISparseVector sv) {
  		if(sv instanceof HashSparseVector){
  			TIntFloatIterator it = ((HashSparseVector) sv).data.iterator();
  			while(it.hasNext()){
  				it.advance();
  				data.adjustOrPutValue(it.key(), it.value(),it.value());
  			}
  		}else if(sv instanceof BinarySparseVector){
  			TIntIterator it = ((BinarySparseVector) sv).data.iterator();
  			while(it.hasNext()){
  				int i = it.next();
  				data.adjustOrPutValue(i,DefaultValue,DefaultValue);
  			}
  		}
  
  	}