whoa

app/src/main/java/sudoku/Sudoku.java

@@ -1,5 +1,9 @@
 package sudoku;
 
+import sudoku.constraint.IConstraint;
+
+import javax.swing.*;
+import java.util.ArrayList;
 import java.util.List;
 
 /**
@@ -22,8 +26,27 @@ public class Sudoku {
 		return this.cells.get(index);
 	}
 
+	public Cell getCell(int i) {
+		return this.cells.get(i);
+	}
+
 	public int getSize() {
 		return this.blocks.size();
 	}
 
+	public Boolean isValid(List<IConstraint> constraints) {
+		//not implemented
+		//for eachcase check contraintes
+		throw new Error("Function isValid() not implemented");
+	}
+
+	public List<MutableCell> getMutableCells() {
+		List<MutableCell> mutableCells = new ArrayList<>();
+		for (Cell cell : this.cells) {
+			if (cell instanceof MutableCell){
+				mutableCells.add((MutableCell) cell);
+			}
+		}
+		return mutableCells;
+	}
 }