code: public int indexOf(int hashCode) {
  		int pos=binarySearchHashCode(hashCode);
  		if(pos<0) return -1;
  
  		// Try backwards until different hashCode
  		while(pos>0 && get(pos-1).hashCode()==hashCode) pos--;
  		return pos;
  	}
docs: Finds the first index where the object has the provided hashCode