<s>
Google	B-Language
Guava	I-Language
is	O
an	O
open-source	O
set	O
of	O
common	O
libraries	O
for	O
Java	B-Language
,	O
mainly	O
developed	O
by	O
Google	B-Application
engineers	O
.	O
</s>
<s>
Google	B-Language
Guava	I-Language
can	O
be	O
roughly	O
divided	O
into	O
three	O
components	O
:	O
basic	O
utilities	O
to	O
reduce	O
manual	O
labor	O
to	O
implement	O
common	O
methods	O
and	O
behaviors	O
,	O
an	O
extension	O
to	O
the	O
Java	B-Language
collections	I-Language
framework	I-Language
(	O
JCF	O
)	O
formerly	O
called	O
the	B-Application
Google	I-Application
Collections	O
Library	O
,	O
and	O
other	O
utilities	O
which	O
provide	O
convenient	O
and	O
productive	O
features	O
such	O
as	O
functional	B-Language
programming	I-Language
,	O
graphs	B-Application
,	O
caching	B-General_Concept
,	O
range	O
objects	O
,	O
and	O
hashing	B-Error_Name
.	O
</s>
<s>
The	O
creation	O
and	O
architecture	O
of	O
the	O
collection	O
component	O
were	O
partly	O
motivated	O
by	O
generics	B-Language
introduced	O
in	O
JDK	B-Language
1.5	O
.	O
</s>
<s>
Although	O
generics	B-Language
improve	O
the	O
productivity	O
of	O
programmers	O
,	O
the	O
standard	O
JCF	O
does	O
not	O
provide	O
sufficient	O
functionality	O
,	O
and	O
its	O
complement	O
Apache	B-Language
Commons	I-Language
Collections	O
had	O
not	O
adopted	O
generics	B-Language
in	O
order	O
to	O
maintain	O
backward	B-General_Concept
compatibility	I-General_Concept
.	O
</s>
<s>
This	O
fact	O
led	O
two	O
engineers	O
Kevin	O
Bourrillion	O
and	O
Jared	O
Levy	O
to	O
develop	O
an	O
extension	O
to	O
JCF	O
,	O
which	O
provides	O
additional	O
generic	O
classes	O
such	O
as	O
multisets	B-Language
,	O
multimaps	B-Language
,	O
bitmaps	O
,	O
and	O
immutable	O
collections	O
.	O
</s>
<s>
The	O
library	O
's	O
design	O
and	O
code	O
were	O
advised	O
and	O
reviewed	O
by	O
Joshua	O
Bloch	O
,	O
the	O
original	O
lead	O
designer	O
of	O
the	O
Java	B-Language
Collections	I-Language
framework	I-Language
,	O
and	O
Doug	O
Lea	O
,	O
one	O
of	O
the	O
lead	O
designers	O
of	O
concurrency	B-Language
utilities	I-Language
in	I-Language
JDK	I-Language
.	O
</s>
<s>
As	O
of	O
April	O
2012	O
,	O
Guava	O
ranked	O
the	O
12th	O
most	O
popular	O
Java	B-Language
library	O
,	O
next	O
to	O
the	O
Apache	B-Language
Commons	I-Language
projects	O
and	O
a	O
few	O
others	O
.	O
</s>
<s>
Research	O
performed	O
in	O
2013	O
on	O
10,000	O
GitHub	B-Application
projects	O
found	O
that	O
Google-made	O
libraries	O
,	O
such	O
as	O
Google	B-Language
Web	I-Language
Toolkit	I-Language
and	O
Guava	O
,	O
constituted	O
7	O
of	O
the	O
top	O
100	O
most	O
popular	O
libraries	O
in	O
Java	B-Language
,	O
and	O
that	O
Guava	O
was	O
the	O
8th	O
most	O
popular	O
Java	B-Language
library	O
.	O
</s>
<s>
As	O
of	O
March	O
2018	O
,	O
Guava	O
was	O
the	O
6th	O
most	O
starred	O
Java	B-Language
project	O
on	O
GitHub	B-Application
.	O
</s>
