private void checkPrototype(DocInfo doc) throws SleighException {
		CompilerSpec cspec = program.getCompilerSpec();
		PrototypeModel[] allModels = cspec.getAllModels();
		for (PrototypeModel model : allModels) {
			if (model.getName().equals(doc.formalName)) {
				if (!model.isProgramExtension()) {
					throw new SleighException(
						"Extension cannot replace prototype: " + doc.formalName);
				}
			}
		}
	}
Check that the proposed prototype extension does not collide with a
built-in prototype.
@param doc is info on the proposed prototype
@throws SleighException if there is a collision
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/SpecExtension.java