   }
 
   func testSendingAFileSpecifiedByURLWithoutMimetype() {
-    if let elonPhotoURL = Bundle(for: JustSendingFiles.self)
-      .url(forResource: "elon", withExtension: "jpg")
-    {
-      let r = Just.post("http://httpbin.org/post",
-                        files: ["elon": .url(elonPhotoURL, nil)])
-      XCTAssertNotNil(r.json)
-      if let data = r.json as? [String: Any] {
-        XCTAssertNotNil(data["files"])
-        if let files = data["files"] as? [String: String] {
-          XCTAssertNotNil(files["elon"])
-        }
-      }
-    } else {
-      XCTFail("resource needed for this test can't be found")
+    let r = Just.post("http://httpbin.org/post",
+                      files: ["elon": .url(elonPhotoURL, nil)])
+    XCTAssertNotNil(r.json)
+    if let data = r.json as? [String: Any] {
+      XCTAssertNotNil(data["files"])
+      if let files = data["files"] as? [String: String] {
+        XCTAssertNotNil(files["elon"])
+      }
     }
   }
 
   func testSendingAFileSpecifiedByURLWithMimetype() {
-    if let elonPhotoURL = Bundle(for: JustSendingFiles.self)
-      .url(forResource: "elon", withExtension: "jpg")
-    {
       let r = Just.post("http://httpbin.org/post",
                         files: ["elon": .url(elonPhotoURL, "image/jpeg")])
       XCTAssertNotNil(r.json)

          XCTAssertNotNil(files["elon"])
        }
      }
    } else {
      XCTFail("resource needed for this test can't be found")
    }
  }

  func testSendingAFileSpecifiedByDataWithoutMimetype() {

}

final class JustSendingFiles: XCTestCase {
  private var elonPhotoURL: URL {
    let lastPathSegmentLength = #file.split(separator: "/").last!.count
    let parentLength = #file.count - lastPathSegmentLength
    let elonPhotoPath = String(#file.prefix(parentLength)) + "elon.jpg"
    return URL(fileURLWithPath: elonPhotoPath)
  }

  func testNotIncludeMultipartHeaderForEmptyFiles() {
    let r = Just.post("http://httpbin.org/post", files: [: ])
    XCTAssertNotNil(r.json)
