final ParsePosition pos = new ParsePosition(0);
        final Date date = format.parse(str, pos);
        if (date == null) {
            return null;
        }
        final int index = pos.getIndex();
        if (index == 0) {
            return null;
        }
        if (index < str.length()) {
            return null;
        }
        return date;
    }

    /**

        final ParsePosition pos = new ParsePosition(0);
        final Date date = format.parse(str, pos);
        if (date == null) {
            return null;
        }
        final int index = pos.getIndex();
        if (index == 0) {
            return null;
        }
        if (index < str.length()) {
            return null;
        }
        return date;
    }

    /**

			return xl.versions[i].header.ModTime > xl.versions[j].header.ModTime
		}) {
			t.Errorf("Contents not sorted")
		}
		for i := range xl.versions {
			hdr := xl.versions[i].header
			ver, err := xl.getIdx(i)
			if err != nil {
				t.Error(err)
				continue
			}
			gotHdr := ver.header()
			if hdr != gotHdr {
				t.Errorf("Header does not match, index: %+v != meta: %+v", hdr, gotHdr)
			}
		}
	}