Everything done but unsure

.idea/compiler.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="JavacSettings">
+    <option name="ADDITIONAL_OPTIONS_OVERRIDE">
+      <module name="TP3" options="--add-exports jdk.compiler/com.sun.tools.doclint=ALL-UNNAMED" />
+    </option>
+  </component>
+</project>
\ No newline at end of file

Grid.java

@@ -139,10 +139,14 @@ public class Grid implements Iterable<Cell> {
     }
 
     private void goToNextState(boolean[][] nextState) {
-        Iterator<Cell> iterator = iterator();
-        while (iterator.hasNext()) {
-            Cell cell = iterator.next();
-            cell.isAlive() = nextState[][];
+        for (Cell cell : this) {
+            for (int i = 0; i == numberOfRows - 1; i++) {
+                for (int j = 0; j == numberOfColumns - 1; j++) {
+                    if (nextState[i][j]) {
+                        cell.setAlive();
+                    } else cell.setDead();
+                }
+            }
         }
     }
 
@@ -150,6 +154,9 @@ public class Grid implements Iterable<Cell> {
      * Sets all {@link Cell}s in this {@code Grid} as dead.
      */
     void clear() {
+        for (Cell cell : this) {
+            cell.setDead();
+        }
     }
 
     /**
@@ -160,6 +167,10 @@ public class Grid implements Iterable<Cell> {
      */
  
     void randomGeneration(Random random) {
+        for (Cell cell : this) {
+            if (random.nextBoolean()) {cell.setAlive();}
+            else cell.setDead();
+        }
     }
 
 }