code: def p_VarTypes(self, p):
          
          n = len(p)
          if n == 4:
              p[0] = ('VarTypes', p[1][1] + [p[3]])
          elif n == 2:
              p[0] = ('VarTypes', [p[1]])
docs: VarTypes : VarTypes ',' VarType
                      | VarType