checkstyle: require tabs for indenting

checkstyle.xml

@@ -6,6 +6,12 @@
 		<module name="LeftCurly">
 			<property name="option" value="nl"/>
 		</module>
+		<!-- require tabs for indenting - https://stackoverflow.com/a/28550141 -->
+		<module name="RegexpSinglelineJava">
+			<property name="format" value="^\t* "/>
+			<property name="message" value="Indent must use tab characters"/>
+			<property name="ignoreComments" value="true"/>
+		</module>
 	</module>
 	<module name="SuppressionFilter">
 		<property name="file" value="suppressions.xml"/>

runelite-api/src/main/java/net/runelite/api/GameState.java

@@ -22,7 +22,6 @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
-
 package net.runelite.api;
 
 public enum GameState
@@ -45,8 +44,12 @@ public enum GameState
 	public static GameState of(int state)
 	{
 		for (GameState gs : GameState.values())
+		{
 			if (gs.state == state)
+			{
 				return gs;
+			}
+		}
 		return UNKNOWN;
 	}
 }