public class TileId
{
    public static final char BUG = '#';
    public static final char EMPTY_SPACE = '.';

    public static boolean valid (char check)
    {
        if ((check == BUG) || (check == EMPTY_SPACE))
            return true;
        else
            return false;
    }

    private TileId ()
    {
    }
}
@@ -6,20 +6,20 @@
 c class 
-Tile
+Cell
 Id%0A%7B%0A   
@@ -48,16 +48,65 @@
 har 
-BUG
+EMPTY_SEAT = 'L';%0A    public static final char FLOOR
  = '
-#
+.
 ';%0A 
@@ -137,24 +137,26 @@
 har 
-EMPTY_SPACE
+OCCUPIED_SEAT
  = '
-.
+#
 ';%0A%0A
@@ -232,11 +232,38 @@
  == 
-BUG
+EMPTY_SEAT) %7C%7C (check == FLOOR
 ) %7C%7C
@@ -277,19 +277,21 @@
  == 
-EMPTY_SPACE
+OCCUPIED_SEAT
 ))%0A 
@@ -376,12 +376,12 @@
 ate 
-Tile
+Cell
 Id (

Update CellId.java