docs: public boolean readLine(Appendable buf) throws IOException {
      boolean success = false;
      while(true) {
        // Process buffer:
        while(pos < end) {
          success = true;
          final char c = buffer[pos++];
          if(c == '\n') {
            return success;
          }
          if(c == '\r') {
            continue;
          }
          buf.append(c);
        }
        // Refill buffer:
        assert (pos >= end) : "Buffer wasn't empty when refilling!";
        end = in.read(buffer, 0, buffer.length);
        pos = 0;
        if(end < 0) { // End of stream.
          return success;
        }
      }
    }