import org.jetbrains.annotations.NotNull; import java.util.*; class Main { private final Map> myScheduledUpdates = null; void foo() { new Runnable() { @Override public void run() { newMethod(); } }; newMethod(); } @NotNull private Object[] newMethod() { return myScheduledUpdates.keySet().toArray(new Object[myScheduledUpdates.keySet().size()]); } }