Rename letters method to fixedString

src/main/java/com/github/javafaker/Faker.java

@@ -240,14 +240,14 @@ public class Faker {
      * Create a string with a fixed size. Can be usefull for testing
      * validator based on length string for example
      *
-     * @param countOfLetters size of the expected String
+     * @param numberOfLetters size of the expected String
      * @return a string with a fixed size
      */
-    public String letters(int countOfLetters) {
+    public String fixedString(int numberOfLetters) {
         StringBuilder builder = new StringBuilder();
-        while (builder.length() < countOfLetters) {
+        while (builder.length() < numberOfLetters) {
             builder.append(sentence());
         }
-        return StringUtils.substring(builder.toString(), 0, countOfLetters);
+        return StringUtils.substring(builder.toString(), 0, numberOfLetters);
     }
 }

src/test/java/com/github/javafaker/FakerTest.java

@@ -43,10 +43,10 @@ public class FakerTest {
 
     @Test
     public void shouldCreateFixedLenghtString() {
-        Assert.assertEquals(10, faker.letters(10).length());
-        Assert.assertEquals(50, faker.letters(50).length());
-        Assert.assertEquals(0, faker.letters(0).length());
-        Assert.assertEquals(0, faker.letters(-1).length());
+        Assert.assertEquals(10, faker.fixedString(10).length());
+        Assert.assertEquals(50, faker.fixedString(50).length());
+        Assert.assertEquals(0, faker.fixedString(0).length());
+        Assert.assertEquals(0, faker.fixedString(-1).length());
     }
 
     @Test