protected HiddenUnit(Unit[] units,double[] weights){
  this.units=units;
  this.weights=new double[weights.length];
  System.arraycopy(weights,0,this.weights,0,weights.length);
}

protected HiddenUnit ( Unit [ ] units , double [ ] weights ) { this . units = units ; this . weights = new double [ weights . length ] ; System . arraycopy ( weights , 0 , this . weights , 0 , weights . length ) ; }
builds a hidden unit taking the provided number of inputs . sets the initial weights to be a copy of the provided weights
