What should i do , to fix this error?

[Kevin-Justin]

C:\flutter.pub-cache\hosted\pub.dartlang.org\simple_permissions-0.1.9\android\src\main\java\com\ethras\simplepermissions\SimplePermissionsPlugin.java:9: error: cannot find symbol
import android.support.v4.app.ActivityCompat;
^
symbol: class ActivityCompat
location: package android.support.v4.app
C:\flutter.pub-cache\hosted\pub.dartlang.org\simple_permissions-0.1.9\android\src\main\java\com\ethras\simplepermissions\SimplePermissionsPlugin.java:10: error: package android.support.v4.content does not exist
import android.support.v4.content.ContextCompat;
^
C:\flutter.pub-cache\hosted\pub.dartlang.org\simple_permissions-0.1.9\android\src\main\java\com\ethras\simplepermissions\SimplePermissionsPlugin.java:156: error: cannot find symbol
ActivityCompat.requestPermissions(activity, perm, 0);
^
symbol: variable ActivityCompat
location: class SimplePermissionsPlugin
C:\flutter.pub-cache\hosted\pub.dartlang.org\simple_permissions-0.1.9\android\src\main\java\com\ethras\simplepermissions\SimplePermissionsPlugin.java:163: error: cannot find symbol
return PackageManager.PERMISSION_GRANTED == ContextCompat.checkSelfPermission(activity, permission);
^
symbol: variable ContextCompat
location: class SimplePermissionsPlugin
C:\flutter.pub-cache\hosted\pub.dartlang.org\simple_permissions-0.1.9\android\src\main\java\com\ethras\simplepermissions\SimplePermissionsPlugin.java:171: error: cannot find symbol
if (ActivityCompat.shouldShowRequestPermissionRationale(registrar.activity(), permission)) {
^
symbol: variable ActivityCompat