private void cleanup() {
		if (process != null) {
			process.destroy();
			process = null;
		}
		if (parser != null) {
			parser.dispose();
			parser = null;
		}
		//errHandler = null;
		//thread = null;
		if (dataTypeParser != null) {
			dataTypeParser.clear();
		}
	}
Checks if PDB has been loaded in the program

@return whether PDB has been loaded or not
Ghidra/Features/PDB/src/main/java/ghidra/app/util/bin/format/pdb/PdbParser.java