code: private void resizeBuffer(int number) {
          int size = newSizeInWords(number);
          if (size >= this.buffer.length) {
              long oldBuffer[] = this.buffer;
              this.buffer = new long[size];
              System.arraycopy(oldBuffer, 0, this.buffer, 0, oldBuffer.length);
          }
  	}
docs: Resizes the buffer if the number of words to add exceeds the buffer capacity.
  @param number the number of words to add