diff --git a/stringCalculator/src/main/java/fr/ippon/stringcalculator/Calculator.java b/stringCalculator/src/main/java/fr/ippon/stringcalculator/Calculator.java
index 61f4a8774f06ced536a168f4165177b650cb0251..1095751fa800735c8009409018ce6b29b4ba4195 100644
--- a/stringCalculator/src/main/java/fr/ippon/stringcalculator/Calculator.java
+++ b/stringCalculator/src/main/java/fr/ippon/stringcalculator/Calculator.java
@@ -5,26 +5,21 @@ import java.util.function.BinaryOperator;
 
 public final class Calculator {
 
-  private Calculator() {
-  }
+  private Calculator() {}
 
   public static String sum(String first, String second) {
     return operate(first, second, BigDecimal::add);
   }
 
-  public static String substract(String first,
-      String second) {
+  public static String substract(String first, String second) {
     return operate(first, second, BigDecimal::subtract);
   }
 
-  private static String operate(String first, String second,
-      BinaryOperator<BigDecimal> operation) {
+  private static String operate(String first, String second, BinaryOperator<BigDecimal> operation) {
     notNull(first);
     notNull(second);
 
-    return operation
-        .apply(toBigDecimal(first), toBigDecimal(second))
-        .toPlainString();
+    return operation.apply(toBigDecimal(first), toBigDecimal(second)).toPlainString();
   }
 
   private static BigDecimal toBigDecimal(String value) {
@@ -40,5 +35,4 @@ public final class Calculator {
       throw new IllegalArgumentException();
     }
   }
-
 }
diff --git a/stringCalculator/src/test/java/fr/ippon/stringcalculator/CalculatorTest.java b/stringCalculator/src/test/java/fr/ippon/stringcalculator/CalculatorTest.java
index 1b4d1668928f07e6611230468d61e6558e2ee073..fdb222dea3635b3af6b028c1eeaf541f731f3ad9 100644
--- a/stringCalculator/src/test/java/fr/ippon/stringcalculator/CalculatorTest.java
+++ b/stringCalculator/src/test/java/fr/ippon/stringcalculator/CalculatorTest.java
@@ -8,16 +8,12 @@ public class CalculatorTest {
 
   @Test
   void shouldNotSumWithNullFirstInput() {
-    assertThatThrownBy(() -> Calculator.sum(null, "3"))
-        .isExactlyInstanceOf(
-            IllegalArgumentException.class);
+    assertThatThrownBy(() -> Calculator.sum(null, "3")).isExactlyInstanceOf(IllegalArgumentException.class);
   }
 
   @Test
   void shouldNotSumWithNullSecondInput() {
-    assertThatThrownBy(() -> Calculator.sum("3", null))
-        .isExactlyInstanceOf(
-            IllegalArgumentException.class);
+    assertThatThrownBy(() -> Calculator.sum("3", null)).isExactlyInstanceOf(IllegalArgumentException.class);
   }
 
   @Test
@@ -42,48 +38,36 @@ public class CalculatorTest {
 
   @Test
   void shouldSumFloats() {
-    assertThat(Calculator.sum("1.01", "2.02"))
-        .isEqualTo("3.03");
+    assertThat(Calculator.sum("1.01", "2.02")).isEqualTo("3.03");
   }
 
   @Test
   void shouldSumCommaSeparatedFloats() {
-    assertThat(Calculator.sum("1,01", "2,02"))
-        .isEqualTo("3.03");
+    assertThat(Calculator.sum("1,01", "2,02")).isEqualTo("3.03");
   }
 
   @Test
   void shouldSumNegativeCommaSeparatedFloats() {
-    assertThat(Calculator.sum("-1,01", "-2,02"))
-        .isEqualTo("-3.03");
+    assertThat(Calculator.sum("-1,01", "-2,02")).isEqualTo("-3.03");
   }
 
   @Test
   void shouldNotSubstractNullInputs() {
-    assertThatThrownBy(
-        () -> Calculator.substract(null, "3"))
-            .isExactlyInstanceOf(
-                IllegalArgumentException.class);
+    assertThatThrownBy(() -> Calculator.substract(null, "3")).isExactlyInstanceOf(IllegalArgumentException.class);
   }
 
   @Test
   void shouldNotSubstractWithNullSecondInputs() {
-    assertThatThrownBy(
-        () -> Calculator.substract("3", null))
-            .isExactlyInstanceOf(
-                IllegalArgumentException.class);
+    assertThatThrownBy(() -> Calculator.substract("3", null)).isExactlyInstanceOf(IllegalArgumentException.class);
   }
 
   @Test
   void shouldSubstractCommaSeparatedFloats() {
-    assertThat(Calculator.substract("1,01", "2,02"))
-        .isEqualTo("-1.01");
+    assertThat(Calculator.substract("1,01", "2,02")).isEqualTo("-1.01");
   }
 
   @Test
   void shouldSumTooBigIntegers() {
-    assertThat(Calculator
-        .sum(String.valueOf(Integer.MAX_VALUE), "2,02"))
-            .isEqualTo("2147483649.02");
+    assertThat(Calculator.sum(String.valueOf(Integer.MAX_VALUE), "2,02")).isEqualTo("2147483649.02");
   }
 }