java code with only a few main entry

java code with only a few main entry

I want to read HBase source code, starting with test cases. I've searched
under the folder /src/test/java, and found
"org/apache/hadoop/hbase/PerformanceEvaluation.java",
"org/apache/hadoop/hbase/rest/PerformanceEvaluation.java"
"org/apache/hadoop/hbase/regionserver/DataBlockEncodingTool.java"
"org/apache/hadoop/hbase/regionserver/EncodedSeekPerformanceTest.java"
have main entry.
But there are many more test source files under the same folder. So I
wonder why only four classes have main entry. Is it sufficient to test
hbase with only the above four main entry?
Since I'm a newbie for Java open source project, anything related will
help. Thanks.