### Question:
UserAdmin implements UserAdminMBean { public boolean removeUser(String name) throws IOException { if (name == null) { throw new IOException("User name cannot be null"); } return userAdmin.removeRole(name); } UserAdmin(org.osgi.service.useradmin.UserAdmin userAdmin); void addCredential(String key, byte[] value, String username); void addCredentialString(String key, String value, String username); boolean addMember(String groupname, String rolename); void addPropertyString(String key, String value, String rolename); void addProperty(String key, byte[] value, String rolename); boolean addRequiredMember(String groupname, String rolename); void createGroup(String name); void createRole(String name); void createUser(String name); CompositeData getAuthorization(String username); TabularData getCredentials(String username); CompositeData getGroup(String groupname); String[] getGroups(String filter); String[] getImpliedRoles(String username); String[] getMembers(String groupname); TabularData getProperties(String rolename); String[] getRequiredMembers(String groupname); CompositeData getRole(String name); String[] getRoles(String filter); CompositeData getUser(String username); String getUserWithProperty(String key, String value); String[] getUsers(String filter); String[] listGroups(); String[] listRoles(); String[] listUsers(); void removeCredential(String key, String username); boolean removeGroup(String name); boolean removeMember(String groupname, String rolename); void removeProperty(String key, String rolename); boolean removeRole(String name); boolean removeUser(String name);  }### Answer:
@Test public void testRemoveUser() throws IOException { Mockito.when(userAdmin.removeRole("user1")).thenReturn(true); boolean isRemoved = mbean.removeUser("user1"); Assert.assertTrue(isRemoved); }