code: function getState(name, isStatic) {
              const stateMap = stack[stack.length - 1];
              const key = `$${name}`; // to avoid "__proto__".
  
              if (!stateMap[key]) {
                  stateMap[key] = {
                      nonStatic: { init: false, get: false, set: false },
                      static: { init: false, get: false, set: false }
                  };
              }
  
              return stateMap[key][isStatic ? "static" : "nonStatic"];
          }
docs: Gets state of a given member name.
  @param {string} name - A name of a member.
  @param {boolean} isStatic - A flag which specifies that is a static member.
  @returns {Object} A state of a given member name.
  - retv.init {boolean} A flag which shows the name is declared as normal member.
  - retv.get {boolean} A flag which shows the name is declared as getter.
  - retv.set {boolean} A flag which shows the name is declared as setter.