PatternSet classesToDelete = fileOperations.patternSet();
        PatternSet sourceToCompile = fileOperations.patternSet();

        prepareFilePatterns(recompilationSpec.getClassesToCompile(), recompilationSpec.getSourcePaths(), classesToDelete, sourceToCompile);
        spec.setSourceFiles(narrowDownSourcesToCompile(sourceTree, sourceToCompile));
        includePreviousCompilationOutputOnClasspath(spec);

    }

    @Override
    public void addChildSpecListener(CopySpecListener copySpecListener) {
        this.listeners.add(copySpecListener);
    }

    @VisibleForTesting
    public Set<Object> getSourcePaths() {
        return sourcePaths.getFrom();
    }

    @Nullable
    public String getDestPath() {
        return destDir == null ? null : PATH_NOTATION_PARSER.parseNotation(destDir);
    }