package adapter; /** * Internally keeps an indentation counter that is initially 0. * Every indentation level is printed as two spaces. */ public interface TreePrinter { /** * Write a string, consider the current indentation. * * @param str * the string to be written */ void println(String str); /** Increment the current indentation by one */ void incIndent(); /** Decrement the current indentation by one */ void decIndent(); }