<s>
JUnit	B-Language
is	O
a	O
unit	O
testing	O
framework	B-Architecture
for	O
the	O
Java	B-Language
programming	I-Language
language	I-Language
.	O
</s>
<s>
JUnit	B-Language
has	O
been	O
important	O
in	O
the	O
development	O
of	O
test-driven	O
development	O
,	O
and	O
is	O
one	O
of	O
a	O
family	O
of	O
unit	O
testing	O
frameworks	O
which	O
is	O
collectively	O
known	O
as	O
xUnit	B-Library
that	O
originated	O
with	O
SUnit	B-Library
.	O
</s>
<s>
JUnit	B-Language
is	O
linked	O
as	O
a	O
JAR	B-Language
at	O
compile-time	O
.	O
</s>
<s>
The	O
latest	O
version	O
of	O
the	O
framework	B-Architecture
,	O
JUnit	B-Language
5	O
,	O
resides	O
under	O
package	O
org.junit.jupiter	O
.	O
</s>
<s>
Previous	O
versions	O
JUnit	B-Language
4	O
and	O
JUnit	B-Language
3	O
were	O
under	O
packages	O
org.junit	O
and	O
junit.framework	O
,	O
respectively	O
.	O
</s>
<s>
A	O
research	O
survey	O
performed	O
in	O
2013	O
across	O
10,000	O
Java	B-Language
projects	O
hosted	O
on	O
GitHub	O
found	O
that	O
JUnit	B-Language
(	O
in	O
a	O
tie	O
with	O
slf4j-api	B-Language
)	O
was	O
the	O
most	O
commonly	O
included	O
external	O
library	O
.	O
</s>
<s>
A	O
JUnit	B-Language
test	O
fixture	O
is	O
a	O
Java	B-Language
object	O
.	O
</s>
<s>
Test	O
methods	O
must	O
be	O
annotated	O
by	O
the	O
@Test	O
annotation	B-Language
.	O
</s>
<s>
According	O
to	O
Martin	O
Fowler	O
,	O
one	O
of	O
the	O
early	O
adopters	O
of	O
JUnit	B-Language
:	O
</s>
<s>
As	O
a	O
side	O
effect	O
of	O
its	O
wide	O
use	O
,	O
previous	O
versions	O
of	O
JUnit	B-Language
remain	O
popular	O
,	O
with	O
JUnit	B-Language
4	O
having	O
over	O
100,000	O
usages	O
by	O
other	O
software	O
components	O
on	O
the	O
Maven	B-Language
Central	O
repository	O
.	O
</s>
<s>
In	O
JUnit	B-Language
4	O
,	O
the	O
annotations	O
for	O
test	O
execution	O
callbacks	O
were	O
@BeforeClass	O
,	O
@Before	O
,	O
@After	O
,	O
and	O
@AfterClass	O
,	O
as	O
opposed	O
to	O
JUnit	B-Language
5	O
's	O
@BeforeAll	O
,	O
@BeforeEach	O
,	O
@AfterEach	O
,	O
and	O
@AfterAll	O
.	O
</s>
<s>
In	O
JUnit	B-Language
3	O
,	O
test	O
fixtures	O
had	O
to	O
inherit	O
from	O
junit.framework.TestCase	O
.	O
</s>
