_src.advance(1 * _security_descriptors);

                if (security_descriptor == null) {
                    if (_security_descriptors < 0 || _security_descriptors > 0xFFFF) throw new NdrException( NdrException.INVALID_CONFORMANCE );
                    security_descriptor = new byte[_security_descriptors];
                }
                _src = _src.derive(_security_descriptori);

                _src.advance(1 * _security_descriptors);

                if ( this.security_descriptor == null ) {
                    if ( _security_descriptors < 0 || _security_descriptors > 0xFFFF )
                        throw new NdrException(NdrException.INVALID_CONFORMANCE);
                    this.security_descriptor = new byte[_security_descriptors];
                }
                _src = _src.derive(_security_descriptori);