Add a failing test.

Making a static method easier accessible for tests.

src/main/java/org/torproject/collector/webstats/SanitizeWeblogs.java

@@ -187,7 +187,7 @@ public class SanitizeWeblogs extends CollecTorMain {
     }
   }
 
-  private static byte[] bytesFor(String line, long times) {
+  public static byte[] bytesFor(String line, long times) {
     return Stream.of(line).limit(times)
         .collect(Collectors.joining("\n", "", "\n")).getBytes();
   }

src/test/java/org/torproject/collector/webstats/SanitizeWeblogsTest.java

@@ -0,0 +1,20 @@
+/* Copyright 2017--2018 The Tor Project
+ * See LICENSE for licensing information */
+
+package org.torproject.collector.webstats;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+
+public class SanitizeWeblogsTest {
+
+  @Test
+  public void bytesForTest() {
+    String lines = "line\nline\nline\nline\nline\n"
+        + "line\nline\nline\nline\nline\n";
+    assertEquals(lines, new String(SanitizeWeblogs.bytesFor("line", 10)));
+  }
+
+}
+