LittleEndianInput in = new LittleEndianInputStream(new ByteArrayInputStream(formulaRawBytes));
byte ptgSid = in.readByte();
switch(ptgSid) {
case AreaPtg.sid: return new AreaPtg(in);
case Area3DPtg.sid: return new Area3DPtg(in);
case RefPtg.sid: return new RefPtg(in);
case Ref3DPtg.sid: return new Ref3DPtg(in);
}
return null;
}