Call the web service in OverviewViewModel

app/src/main/java/com/example/android/marsphotos/overview/OverviewViewModel.kt

@@ -19,6 +19,9 @@ package com.example.android.marsphotos.overview
 import androidx.lifecycle.LiveData
 import androidx.lifecycle.MutableLiveData
 import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import com.example.android.marsphotos.network.MarsApi
+import kotlinx.coroutines.launch
 
 /**
  * The [ViewModel] that is attached to the [OverviewFragment].
@@ -42,6 +45,9 @@ class OverviewViewModel : ViewModel() {
      * [MarsPhoto] [List] [LiveData].
      */
     private fun getMarsPhotos() {
-        _status.value = "Set the Mars API status response here!"
+        viewModelScope.launch {
+            val listResult = MarsApi.retrofitService.getPhotos()
+            _status.value = listResult
+        }
     }
 }