deploy mineV3 && add ERC20Helper

contracts/helper/ERC20Helper.sol

@@ -0,0 +1,42 @@
+/*
+
+    Copyright 2021 DODO ZOO.
+    SPDX-License-Identifier: Apache-2.0
+
+*/
+
+pragma solidity 0.6.9;
+
+interface IERC20ForCheck {
+    function decimals() external view returns (uint);
+    function name() external view returns (string memory);
+    function symbol() external view returns (string memory);
+
+    function balanceOf(address account) external view returns (uint256);
+    function allowance(address owner, address spender) external view returns (uint256);
+}
+
+
+contract ERC20Helper {
+    function isERC20(address token, address user, address spender) external view returns(bool isOk, string memory symbol, string memory name, uint decimals, uint256 balance, uint256 allownance) {
+        try this.judgeERC20(token, user, spender) returns (string memory _symbol, string memory _name, uint _decimals, uint256 _balance, uint256 _allownance) {
+            symbol = _symbol;
+            name = _name;
+            decimals = _decimals;
+            balance = _balance;
+            allownance = _allownance;
+            isOk = true;
+        } catch {
+            isOk = false;
+        }      
+    }
+
+   function judgeERC20(address token, address user, address spender) external view returns(string memory symbol, string memory name, uint decimals, uint256 balance, uint256 allownance) {
+        name = IERC20ForCheck(token).name();
+        symbol = IERC20ForCheck(token).symbol();
+        decimals = IERC20ForCheck(token).decimals();
+        
+        balance = IERC20ForCheck(token).balanceOf(user);
+        allownance = IERC20ForCheck(token).allowance(user,spender);
+   }
+}