code: public static String collectContent(InputBuffer buf) {
          StringBuilder sb = new StringBuilder();
          int ix = 0;
  
          loop:
          while (true) {
              char c = buf.charAt(ix++);
              switch (c) {
                  case INDENT:
                      sb.append('\u00bb'); // right pointed double angle quotation mark
                      break;
                  case DEDENT:
                      sb.append('\u00ab'); // left pointed double angle quotation mark
                      break;
                  case EOI:
                      break loop;
                  default:
                      sb.append(c);
              }
          }
          return sb.toString();
      }
docs: Collects the actual input text the input buffer provides into a String.
  This is especially useful for IndentDedentInputBuffers created by "transformIndents".
  @param buf the input buffer to collect from
  @return a string containing the content of the given input buffer