code: public boolean skipPreamble()
              throws IOException {
          // First delimiter may be not preceeded with a CRLF.
          System.arraycopy(boundary, 2, boundary, 0, boundary.length - 2);
          boundaryLength = boundary.length - 2;
          try {
              // Discard all data up to the delimiter.
              discardBodyData();
  
              // Read boundary - if succeded, the stream contains an
              // encapsulation.
              return readBoundary();
          } catch (MalformedStreamException e) {
              return false;
          } finally {
              // Restore delimiter.
              System.arraycopy(boundary, 0, boundary, 2, boundary.length - 2);
              boundaryLength = boundary.length;
              boundary[0] = CR;
              boundary[1] = LF;
          }
      }
docs: Finds the beginning of the first <code>encapsulation</code>.
  
  @return <code>true</code> if an <code>encapsulation</code> was found in
  the stream.
  
  @throws IOException if an i/o error occurs.