Enhancements to compilation unit retrieval.

- Encapsulate.
- Clear cache.

Author: khatchad

edu.cuny.hunter.streamrefactoring.core/src/edu/cuny/hunter/streamrefactoring/core/refactorings/ConvertToParallelStreamRefactoringProcessor.java

@@ -276,6 +276,7 @@ private RefactoringStatus checkWritabilitiy(IMember member, PreconditionFailure
 	public void clearCaches() {
 		getTypeToTypeHierarchyMap().clear();
 		getCompilationUnitToCompilationUnitRewriteMap().clear();
+		getTypeRootToCompilationUnitMap().clear();
 		Stream.clearCaches();
 	}
 
@@ -333,12 +334,12 @@ private RefactoringStatus createWorkingCopyLayer(IProgressMonitor monitor) {
 	}
 
 	private CompilationUnit getCompilationUnit(ITypeRoot root, IProgressMonitor pm) {
-		CompilationUnit compilationUnit = this.typeRootToCompilationUnitMap.get(root);
+		CompilationUnit compilationUnit = this.getTypeRootToCompilationUnitMap().get(root);
 		if (compilationUnit == null) {
 			this.getExcludedTimeCollector().start();
 			compilationUnit = RefactoringASTParser.parseWithASTProvider(root, true, pm);
 			this.getExcludedTimeCollector().stop();
-			this.typeRootToCompilationUnitMap.put(root, compilationUnit);
+			this.getTypeRootToCompilationUnitMap().put(root, compilationUnit);
 		}
 		return compilationUnit;
 	}
@@ -401,6 +402,10 @@ private Map<IType, ITypeHierarchy> getTypeToTypeHierarchyMap() {
 		return typeToTypeHierarchyMap;
 	}
 
+	protected Map<ITypeRoot, CompilationUnit> getTypeRootToCompilationUnitMap() {
+		return typeRootToCompilationUnitMap;
+	}
+
 	@Override
 	public boolean isApplicable() throws CoreException {
 		// return