Add unit tests for NewOrderResponse.

Author: joaopsilva

src/main/java/com/binance/api/client/domain/account/NewOrderResponse.java

@@ -53,6 +53,7 @@ public class NewOrderResponse {
 
   private OrderSide side;
 
+  // @JsonSetter(nulls = Nulls.AS_EMPTY)
   private List<Trade> fills;
 
   /**

src/test/java/com/binance/api/client/domain/account/NewOrderResponseTest.java

@@ -0,0 +1,49 @@
+package com.binance.api.client.domain.account;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+
+import static org.hamcrest.CoreMatchers.containsString;
+import static org.hamcrest.CoreMatchers.is;
+import static org.junit.Assert.assertThat;
+
+/**
+ * @see NewOrderResponse
+ */
+public class NewOrderResponseTest {
+
+  private NewOrderResponse newOrderResponse;
+  private Trade trade;
+
+  @Before
+  public void setUp() {
+    newOrderResponse = new NewOrderResponse();
+    trade = new Trade();
+    trade.setId(123L);
+  }
+
+  @Test
+  public void shouldHandleToStringWithNullFills() {
+    assertThat(newOrderResponse.toString(), containsString(",fills="));
+  }
+
+  @Test
+  public void shouldHandleToStringWithNoFills() {
+    newOrderResponse.setFills(Collections.emptyList());
+    assertThat(newOrderResponse.toString(), containsString(",fills="));
+  }
+
+  @Test
+  public void shouldHandleToStringWithFills() {
+    newOrderResponse.setFills(trades(trade));
+    assertThat(newOrderResponse.toString(), containsString(",fills=Trade[id=123,"));
+  }
+
+  private static List<Trade> trades(final Trade... trades) {
+    return Arrays.asList(trades);
+  }
+}