type (
		testHeader struct { // WriteHeader(hdr) == wantErr
			hdr     Header
			wantErr error
		}
		testWrite struct { // Write(str) == (wantCnt, wantErr)
			str     string
			wantCnt int
			wantErr error
		}
		testReadFrom struct { // ReadFrom(testFile{ops}) == (wantCnt, wantErr)
			ops     fileOps
			wantCnt int64
			wantErr error
		}
		testClose struct { // Close() == wantErr
			wantErr error
		}

}

func TestFileReader(t *testing.T) {
	type (
		testRead struct { // Read(cnt) == (wantStr, wantErr)
			cnt     int
			wantStr string
			wantErr error
		}
		testWriteTo struct { // WriteTo(testFile{ops}) == (wantCnt, wantErr)
			ops     fileOps
			wantCnt int64
			wantErr error
		}
		testRemaining struct { // logicalRemaining() == wantLCnt, physicalRemaining() == wantPCnt

			br := NewReaderSize(r, size)
			want := func(s string, wantErr error) {
				p := make([]byte, 50)
				n, err := br.Read(p)
				if err != wantErr || n != len(s) || string(p[:n]) != s {
					t.Fatalf("read(%d) = %q, %v, want %q, %v", len(p), string(p[:n]), err, s, wantErr)
				}
				t.Logf("read(%d) = %q, %v", len(p), string(p[:n]), err)
			}
			want("abc", nil)

			}
			var apiErr APIErrorResponse
			err = xml.Unmarshal(b, &apiErr)
			if err != nil {
				t.Fatal(err)
			}
			gotErr := apiErr.Code
			wantErr := testCase.wantAPICode
			if gotErr != wantErr {
				t.Errorf("test %d: want api error %q, got %q", i, wantErr, gotErr)
			}
			if testCase.wantHeaders != nil {
				for k, v := range testCase.wantHeaders {
					got := rec.Header().Get(k)
					if got != v {