Library is not importing after changing from 'compile' to 'implementation/api'

[gmptr5797]

Library is not importing after changing from 'compile' to 'implementation/api'
Showing error as 'Cannot resolve symbol' for below imports
import com.unnamed.b.atv.model.TreeNode;
import com.unnamed.b.atv.view.AndroidTreeView;

Gradle
implementation 'com.github.bmelnychuk:atv:1.2.9'
minSdkVersion 21
compileSdkVersion 26
targetSdkVersion 26
buildToolsVersion '28.0.3'
Gradle Version : 3.2.1