protected virtual void Parse(string str, ref int pos, int len)
{
mUDegree = int.Parse(ParserSTEP.StripField(str, ref pos, len));
mVDegree = int.Parse(ParserSTEP.StripField(str, ref pos, len));
mControlPointsList = ParserSTEP.StripListListLink(str, ref pos, len);
string s = ParserSTEP.StripField(str, ref pos, len);
if(s[0] == '.')
Enum.TryParse<IfcBSplineSurfaceForm>(s.Replace(".", ""),out mSurfaceForm);
mUClosed = ParserIfc.StripLogical(str,ref pos, len);
mVClosed = ParserIfc.StripLogical(str,ref pos, len);
mSelfIntersect = ParserIfc.StripLogical(str,ref pos, len);
}