920         self.assertEqual(b"b", bufio.read1(1))
922         self.assertEqual(b"c", bufio.read1(100))
924         self.assertEqual(b"d", bufio.read1(100))
926         self.assertEqual(b"efg", bufio.read1(100))
928         self.assertEqual(b"", bufio.read1(100))
931         self.assertRaises(ValueError, bufio.read1, -1)
1497         self.assertEqual(pair.read1(3), b"abc")
1747             bufio.read1(1)
1821                 self.assertEqual(f.read1(1), b'd')
2670             read1 = self.StringIO.read  variable in TextIOWrapperTest.test_read_nonbytes.NonbytesStream
2672             read1 = self.StringIO.read  variable in TextIOWrapperTest.test_read_nonbytes.NonbytesStream
3005                 self.assertRaises(ValueError, f.read1, 1024)