code: public long skip(long n) throws IOException {
          int available = ofinish - ostart;
          if (n > available) {
              n = available;
          }
          if (n < 0) {
              return 0;
          }
          ostart += n;
          return n;
      }
docs: Skips <code>n</code> bytes of input from the bytes that can be read
  from this input stream without blocking.
  
  <p>Fewer bytes than requested might be skipped.
  The actual number of bytes skipped is equal to <code>n</code> or
  the result of a call to
  {@link #available() <code>available</code>},
  whichever is smaller.
  If <code>n</code> is less than zero, no bytes are skipped.
  
  <p>The actual number of bytes skipped is returned.
  
  @param      n the number of bytes to be skipped.
  @return     the actual number of bytes skipped.
  @exception  IOException  if an I/O error occurs.
  @since JCE1.2