code: public int indexOf(int[] sequence) {
          int index = -1;
          for (int i = 0; index == -1 && i <= currentSize - sequence.length;
               i++) {
              if (buffer[i] == sequence[0]) {
                  boolean matches = true;
                  for (int j = 1; matches && j < sequence.length; j++) {
                      if (buffer[i + j] != sequence[j]) {
                          matches = false;
                      }
                  }
                  if (matches) {
                      index = i;
                  }
              }
          }
          return index;
      }
docs: finds sequence in current buffer.
  
  @return index of sequence or -1 if not found