@Override
    public void visitClassContext(ClassContext classContext) {
        try {
            unusedParms = new BitSet();
            regToParm = new HashMap<>();
            stack = new OpcodeStack();
            super.visitClassContext(classContext);
        } finally {
            stack = null;
            regToParm = null;
            unusedParms.clear();
        }
    }
@ Override public void visitClassContext ( ClassContext classContext ) { try { unusedParms = new BitSet ( ) ; regToParm = new HashMap < > ( ) ; stack = new OpcodeStack ( ) ; super . visitClassContext ( classContext ) ; } finally { stack = null ; regToParm = null ; unusedParms . clear ( ) ; } }
implements the visitor to create parm bitset

@param classContext
the context object of the currently parsed class