tw.check(t, "abc12345", "6789012345") // use Write and then WriteString since the remaining part is still longer than BufSize
	}
	{
		tw := &teststringwriter{}
		b := NewWriterSize(tw, BufSize)
		b.Write([]byte("abc")) // same as above, but use Write instead of WriteString
		tw.check(t, "", "")
		b.WriteString("123456789012345")
		tw.check(t, "abc12345", "6789012345") // same as above
	}
}

0xb00327c8, 6, 7, 0, 1, 2, 3, 4, 5) SHA256ROUND1(27, 0xbf597fc7, 5, 6, 7, 0, 1, 2, 3, 4) SHA256ROUND1(28, 0xc6e00bf3, 4, 5, 6, 7, 0, 1, 2, 3) SHA256ROUND1(29, 0xd5a79147, 3, 4, 5, 6, 7, 0, 1, 2) SHA256ROUND1(30, 0x06ca6351, 2, 3, 4, 5, 6, 7, 0, 1) SHA256ROUND1(31, 0x14292967, 1, 2, 3, 4, 5, 6, 7, 0) SHA256ROUND1(32, 0x27b70a85, 0, 1, 2, 3, 4, 5, 6, 7) SHA256ROUND1(33, 0x2e1b2138, 7, 0, 1, 2, 3, 4, 5, 6) SHA256ROUND1(34, 0x4d2c6dfc, 6, 7, 0, 1, 2, 3, 4, 5) SHA256ROUND1(35, 0x53380d13, 5, 6, 7, 0, 1, 2, 3,...