Fix ModelTest

Author: pengrad

library/src/main/java/com/pengrad/telegrambot/model/BotCommand.java

@@ -14,7 +14,7 @@ public BotCommand(String command, String description) {
         this.description = description;
     }
 
-    private BotCommand() {}
+    BotCommand() {}
 
     private String command;
     private String description;

library/src/test/java/com/pengrad/telegrambot/ModelTest.java

@@ -7,13 +7,13 @@
 import com.pengrad.telegrambot.model.request.InlineKeyboardButton;
 import com.pengrad.telegrambot.model.request.InlineKeyboardMarkup;
 import com.pengrad.telegrambot.passport.Credentials;
-import nl.jqno.equalsverifier.EqualsVerifier;
-import nl.jqno.equalsverifier.Warning;
+
 import org.junit.Before;
 import org.junit.Test;
 import org.reflections.Reflections;
 import org.reflections.scanners.SubTypesScanner;
 
+import java.lang.reflect.Constructor;
 import java.lang.reflect.Field;
 import java.lang.reflect.Modifier;
 import java.util.Arrays;
@@ -23,6 +23,9 @@
 import java.util.function.Supplier;
 import java.util.stream.Collectors;
 
+import nl.jqno.equalsverifier.EqualsVerifier;
+import nl.jqno.equalsverifier.Warning;
+
 import static org.junit.Assert.assertTrue;
 
 /**
@@ -85,9 +88,9 @@ public void testEquals() throws IllegalAccessException, InstantiationException,
     }
 
     @Test
-    public void testToString() throws IllegalAccessException, InstantiationException {
+    public void testToString() throws Exception {
         for (Class c : classes) {
-            Object instance = customInstance.containsKey(c) ? customInstance.get(c).get() : c.newInstance();
+            Object instance = customInstance.containsKey(c) ? customInstance.get(c).get() : defaultInstance(c);
             String toString = instance.toString();
             for (Field f : c.getDeclaredFields()) {
                 if (Modifier.isStatic(f.getModifiers())) {
@@ -97,4 +100,10 @@ public void testToString() throws IllegalAccessException, InstantiationException
             }
         }
     }
+
+    private Object defaultInstance(Class c) throws Exception {
+        Constructor constructor = c.getDeclaredConstructor();
+        constructor.setAccessible(true);
+        return constructor.newInstance();
+    }
 }