int read4(char[] buff) {
        buff[0] = 'a';
        buff[1] = 'b';
        buff[2] = 'c';
        buff[3] = 'd';
        return 4;
    }
Date 03/26/2016
@author Tushar Roy

Given a reader which only reads 4 bytes implement a Reader which can read bytes of give size.

Reference
Read N Characters Given Read4 II
https://leetcode.com/problems/read-n-characters-given-read4-ii-call-multiple-times/
src/com/interview/misc/Read4Function.java