code: function isValidThisArg(expectedThis, thisArg, context) {
      if (!expectedThis) {
          return astUtils.isNullOrUndefined(thisArg);
      }
      return astUtils.equalTokens(expectedThis, thisArg, context);
  }
docs: Checks whether or not `thisArg` is not changed by `.apply()`.
  @param {ASTNode|null} expectedThis - The node that is the owner of the applied function.
  @param {ASTNode} thisArg - The node that is given to the first argument of the `.apply()`.
  @param {RuleContext} context - The ESLint rule context object.
  @returns {boolean} Whether or not `thisArg` is not changed by `.apply()`.