Internal compiler error
java.lang.NullPointerException
	at org.eclipse.jdt.internal.compiler.lookup.ReferenceBinding.needsUncheckedConversion(ReferenceBinding.java:660)
	at org.eclipse.jdt.internal.compiler.ast.ReturnStatement.resolve(ReturnStatement.java:222)
	at org.eclipse.jdt.internal.compiler.ast.IfStatement.resolve(IfStatement.java:224)
	at org.eclipse.jdt.internal.compiler.ast.Block.resolveUsing(Block.java:115)
	at org.eclipse.jdt.internal.compiler.ast.SynchronizedStatement.resolve(SynchronizedStatement.java:172)
	at org.eclipse.jdt.internal.compiler.ast.AbstractMethodDeclaration.resolveStatements(AbstractMethodDeclaration.java:400)
	at org.eclipse.jdt.internal.compiler.ast.MethodDeclaration.resolveStatements(MethodDeclaration.java:147)
	at org.eclipse.jdt.internal.compiler.ast.AbstractMethodDeclaration.resolve(AbstractMethodDeclaration.java:378)
	at org.eclipse.jdt.internal.compiler.ast.TypeDeclaration.resolve(TypeDeclaration.java:985)
	at org.eclipse.jdt.internal.compiler.ast.TypeDeclaration.resolve(TypeDeclaration.java:1034)
	at org.eclipse.jdt.internal.compiler.ast.CompilationUnitDeclaration.resolve(CompilationUnitDeclaration.java:280)
	at org.eclipse.jdt.internal.compiler.Compiler.process(Compiler.java:510)
	at org.eclipse.jdt.internal.compiler.Compiler.compile(Compiler.java:335)
	at org.eclipse.jdt.internal.core.builder.AbstractImageBuilder.compile(AbstractImageBuilder.java:209)
	at org.eclipse.jdt.internal.core.builder.AbstractImageBuilder.compile(AbstractImageBuilder.java:159)
	at org.eclipse.jdt.internal.core.builder.BatchImageBuilder.build(BatchImageBuilder.java:49)
	at org.eclipse.jdt.internal.core.builder.JavaBuilder.buildAll(JavaBuilder.java:212)
	at org.eclipse.jdt.internal.core.builder.JavaBuilder.build(JavaBuilder.java:140)
	at org.eclipse.core.internal.events.BuildManager$2.run(BuildManager.java:574)
	at org.eclipse.core.internal.runtime.InternalPlatform.run(InternalPlatform.java:616)
	at org.eclipse.core.runtime.Platform.run(Platform.java:747)
	at org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:158)
	at org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:192)
	at org.eclipse.core.internal.events.BuildManager$1.run(BuildManager.java:221)
	at org.eclipse.core.internal.runtime.InternalPlatform.run(InternalPlatform.java:616)
	at org.eclipse.core.runtime.Platform.run(Platform.java:747)
	at org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:224)
	at org.eclipse.core.internal.events.BuildManager.basicBuildLoop(BuildManager.java:243)
	at org.eclipse.core.internal.events.BuildManager.build(BuildManager.java:272)
	at org.eclipse.core.internal.events.AutoBuildJob.doBuild(AutoBuildJob.java:142)
	at org.eclipse.core.internal.events.AutoBuildJob.run(AutoBuildJob.java:203)
	at org.eclipse.core.internal.jobs.Worker.run(Worker.java:66)