Check optional node code

[FabriceSalvaire]

Complicated for just BJT

[xesscorp]

I may have a problem related to this. When I parse a library with the following code:

.subckt test 2
Q1 N003 2 N006 0 N temp=27
.model N NPN(BF=125 Cjc=40p Re=9.87K)
.ends test

the parser (Parser.py, line 467) outputs:

Q1 N003 2 N006 0 N temp=27

When I remove the substrate connection from Q1:

.subckt test 2
Q1 N003 2 N006 N temp=27
.model N NPN(BF=125 Cjc=40p Re=9.87K)
.ends test

the parser doesn't emit the warning message.