fix ci error

Author: inhere

.travis.yml

@@ -2,7 +2,7 @@ language: php
 
 php:
 #  - '7.1'
-  - '7.2'
+#  - '7.2'
   - '7.3'
   - '7.4'
 

src/AbstractHandler.php

@@ -160,12 +160,19 @@ public function __construct(Input $input, Output $output, InputDefinition $defin
         $this->commentsVars = $this->annotationVars();
 
         $this->init();
+
+        $this->afterInit();
     }
 
     protected function init(): void
     {
     }
 
+    protected function afterInit(): void
+    {
+        // do something...
+    }
+
     /**
      * Configure input definition for command, like symfony console.
      */