code: private void addMissingBlanks(final int index) {
  		final int count = index - this.list.size();
  		for (int i = 0; i < count; i++)
  			this.list.add(this.blankElement);
  	}
  
  	/** Postcondition: this.list.get(this.list.size()-1) != blankElement */
  	private void removeTrail() {
  		int last = this.list.size() - 1;
  		while (last >= 0 && this.list.get(last) == this.blankElement) {
  			this.list.remove(last);
  			last = this.list.size() - 1;
  		}
  	}
  
      /**
       * @return the capacity of the full list
       */
      public int capacity() {
  		if (this.capacity < this.list.size())
  			this.capacity = this.list.size();
  
  		return this.capacity;
      }
  }
docs: Postcondition: this.list.size() == index