LineMarkerProvider not working?!

I want to develop a plugin, with that one can attach a marker to the current line via the context menu in the editor.For that I have created a new class that implements the LineMarkerInfo interface.

package de.vag.intellij.marker

import com.intellij.codeInsight.daemon.LineMarkerInfo
import com.intellij.codeInsight.daemon.LineMarkerProvider
import com.intellij.psi.PsiElement
import com.intellij.openapi.editor.markup.GutterIconRenderer
import com.intellij.openapi.util.IconLoader

class MyMarkerProvider() : LineMarkerProvider {

    override fun getLineMarkerInfo(element: PsiElement): LineMarkerInfo<*>? {
        val icon = IconLoader.getIcon("/META-INF/logo.svg")
        return LineMarkerInfo(element, element.textRange, icon, null,null, GutterIconRenderer.Alignment.LEFT)
    }
}

Then I Have registered this new class in the Plugin.xml (for Java).

<extensions defaultExtensionNs="com.intellij">
    <codeInsight.lineMarkerProvider
            language="JAVA"
            implementationClass="de.vag.intellij.marker.MyMarkerProvider"/>
</extensions>

I call the getLineMarkerInfo() in the action listener of the menu option:

package de.vag.intellij

import de.vag.intellij.marker.MyMarkerProvider
import com.intellij.openapi.actionSystem.AnAction
import com.intellij.openapi.actionSystem.AnActionEvent
import com.intellij.openapi.actionSystem.CommonDataKeys
import com.intellij.openapi.actionSystem.LangDataKeys
import com.intellij.psi.PsiElement

class MarkerAction : AnAction() {
    override fun actionPerformed(e: AnActionEvent) {
        val editor = e.getRequiredData(CommonDataKeys.EDITOR)
        val psiElement: PsiElement = e.getData(LangDataKeys.PSI_FILE)!!
        MyMarkerProvider().getLineMarkerInfo(psiElement)
    }
}

The method gets called but nothing happens and no error occurs.  So what am I missing?