code: public void writeBytes(byte[] src, int srcStart, int destStart, int len) {
  
          int newEnd = destStart + len;
          ensureCapacity(newEnd);
          if (newEnd > m_size) {
              m_size = newEnd;
          }
          System.arraycopy(src, srcStart, m_buffer, destStart, len);
      }
docs: Writes some bytes to this buffer, expanding the buffer if necessary.<p>
  
  @param src the source from which to write the bytes
  @param srcStart the start index in the source array
  @param destStart the start index in this buffer
  
  @param len the number of bytes to write