This instruction assigns a class literal to a variable and then never uses it. The behavior of this differs in Java 1.4 and in Java 5. In Java 1.4 and earlier, a reference to Foo.class would force the static initializer for Foo to be executed, if it has not been executed already. In Java 5 and later, it does not.

See Sun's article on Java SE compatibility for more details and examples, and suggestions on how to force class initialization in Java 5.
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DLS: In class com.sun.javatest.mrep.ReportDirChooser
In class com.sun.javatest.mrep.ReportDirChooser
In method com.sun.javatest.mrep.ReportDirChooser.<static initializer>()
Local variable named reportClass
Type com.sun.javatest.report.Report
At ReportDirChooser.java:[line 54]
Dead store of com.sun.javatest.report.Report.class in com.sun.javatest.mrep.ReportDirChooser.<static initializer>()
   DLS: In class com.sun.javatest.report.ReportDirChooser
In class com.sun.javatest.report.ReportDirChooser
In method com.sun.javatest.report.ReportDirChooser.<static initializer>()
Local variable named reportClass
Type com.sun.javatest.report.Report
At ReportDirChooser.java:[line 53]
Dead store of com.sun.javatest.report.Report.class in com.sun.javatest.report.ReportDirChooser.<static initializer>()
   DLS: In class com.sun.javatest.tool.TestSuiteChooser
In class com.sun.javatest.tool.TestSuiteChooser
In method com.sun.javatest.tool.TestSuiteChooser.<static initializer>()
Local variable named testSuiteClass
Type com.sun.javatest.TestSuite
At TestSuiteChooser.java:[line 48]
Dead store of com.sun.javatest.TestSuite.class in com.sun.javatest.tool.TestSuiteChooser.<static initializer>()
   DLS: In class com.sun.javatest.tool.WorkDirChooser
In class com.sun.javatest.tool.WorkDirChooser
In method com.sun.javatest.tool.WorkDirChooser.<static initializer>()
Local variable named workDirClass
Type com.sun.javatest.WorkDirectory
At WorkDirChooser.java:[line 51]
Dead store of com.sun.javatest.WorkDirectory.class in com.sun.javatest.tool.WorkDirChooser.<static initializer>()