static VerifySupplier apply(VerifySupplier verifySupplier) {
        return verifySupplier;
    }
Returns itself, this mainly helps to write smooth code.
@param verifySupplier verifySupplier
@return verifySupplier
shenyu-plugin/shenyu-plugin-security/shenyu-plugin-sign/src/main/java/org/apache/shenyu/plugin/sign/api/VerifySupplier.java