### Question:
DataFrameReader { public Table url(String url) throws IOException { return url(new URL(url)); } DataFrameReader(ReaderRegistry registry); Table url(String url); Table url(URL url); Table string(String s, String fileExtension); Table file(String file); Table file(File file); Table usingOptions(T options); Table usingOptions(ReadOptions.Builder builder); Table db(ResultSet resultSet); Table db(ResultSet resultSet, String tableName); Table csv(String file); Table csv(String contents, String tableName); Table csv(File file); Table csv(InputStream stream); Table csv(URL url); Table csv(InputStream stream, String name); Table csv(Reader reader); Table csv(CsvReadOptions.Builder options); Table csv(CsvReadOptions options);  }### Answer:
@Test public void readUrlWithExtension() throws Exception { URL url = mockUrlHelper( "http: Table expected = Table.create(StringColumn.create("region", new String[] {"canada", "us"})); Table actual = Table.read().url(url); assertEquals(expected.columnNames(), actual.columnNames()); assertEquals(expected.stringColumn(0).asList(), actual.stringColumn(0).asList()); }
@Test public void readUrlUnknownMimeTypeNoExtension() throws Exception { URL url = mockUrlHelper("http: Throwable thrown = assertThrows(IllegalArgumentException.class, () -> Table.read().url(url)); assertTrue( thrown .getMessage() .contains("No reader registered for mime-type application/octet-stream")); }