private boolean writeDependClasses() {
		int size = classList.size();
		if (size > 0) {
			for (int i = 0; i < size; i++) {
				Class<?> clazz = classList.get(i);
				String caKey = XsonSupport.getCustomAgreementKey(clazz);
				if (null == caKey) {
					byte[] strBuf = clazz.getName().getBytes(this.charset);
					append(new byte[] { XsonConst.CLASS_DES,
							(byte) strBuf.length });
					append(strBuf);
				} else {
					byte[] strBuf = caKey.getBytes(this.charset);
					append(new byte[] { XsonConst.CLASS_REF,
							(byte) strBuf.length });
					append(strBuf);
				}
			}
			return true;
		} else {
			return false;
		}
	}