code: public double get(int i) {
  		if (i < 0 || i >= N) throw new IllegalArgumentException("Illegal index " + i + " should be > 0 and < " + N);
  		if (symbolTable.contains(i)) return symbolTable.get(i);
  		else                return 0.0;
  	}
docs: get a value
  
  @param i
  @return  return symbolTable[i]