### Question:
JenkinsDefaultURLProvider { public String getDefaultJenkinsURL() { String jenkinsURL = getJENKINS_URL(); if (jenkinsURL != null && jenkinsURL.trim().length() > 0) { return jenkinsURL; } return getLocalhostURL(); }  String getDefaultJenkinsURL(); String createDefaultURLDescription();  }### Answer:
@Test public void system_provider_returns_null_for_JENKINS_URL___then_fallback_url_with_localhost_is_returned() { when(mockedSystemAdapter.getEnv("JENKINS_URL")).thenReturn(null); assertEquals("http: }
@Test public void system_provider_returns_empty_string_for_JENKINS_URL___then_fallback_url_with_localhost_is_returned() { when(mockedSystemAdapter.getEnv("JENKINS_URL")).thenReturn(""); assertEquals("http: }
@Test public void system_provider_returns_blubber_for_JENKINS_URL___then_blubber_is_returned() { when(mockedSystemAdapter.getEnv("JENKINS_URL")).thenReturn("blubber"); assertEquals("blubber", providerToTest.getDefaultJenkinsURL()); }