code: private void indent() throws IOException {
          if (indent>=0) {
              out.write('\n');
              for (int i=indent*2; i>0; ) {
                  int len = Math.min(i,INDENT.length);
                  out.write(INDENT,0,len);
                  i-=len;
              }
          }
      }
docs: Prints indentation.