public OutputBuilder inputResource(String resourceName) throws IOException {
            if (resourceName == null) {
                throw new NullPointerException("resourceName");
            }
            Path path = createTempFile("csv");
            EmbulkTests.copyResource(resourceName, path);
            return inputPath(path);
        }
This method returns PreviewResult.

@return PreviewResult returns the result by PreviewExecutor
@throws IOException in case of failures in file operations
embulk-junit4/src/main/java/org/embulk/test/TestingEmbulk.java