web/src/main/java/org/springframework/security/web/savedrequest/SavedRequestAwareWrapper.java
@Override
	public long getDateHeader(String name) {
		String value = getHeader(name);

		if (value == null) {
			return -1L;
		}

		// Attempt to convert the date header in a variety of formats
		long result = FastHttpDateFormat.parseDate(value, formats);

		if (result != -1L) {
			return result;
		}

		throw new IllegalArgumentException(value);
	}
@Override
	public long getDateHeader(String name) {
		String value = getHeader(name);

		if (value == null) {
			return -1L;
		}

		// Attempt to convert the date header in a variety of formats
		long result = FastHttpDateFormat.parseDate(value, formats);

		if (result != -1L) {
			return result;
		}

		throw new IllegalArgumentException(value);
	}
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