jetbrick-commons/src/main/java/jetbrick/io/buffer/FastBuffer.java
public FastBuffer<E> append(FastBuffer<E> buff) {
        if (buff.size == 0) {
            return this;
        }
        for (int i = 0; i < buff.currentBufferIndex; i++) {
            append(buff.buffers[i]);
        }
        append(buff.currentBuffer, 0, buff.offset);
        return this;
    }
public FastBuffer<E> append(FastBuffer<E> buff) {
        if (buff.size == 0) {
            return this;
        }
        for (int i = 0; i < buff.currentBufferIndex; i++) {
            append(buff.buffers[i]);
        }
        append(buff.currentBuffer, 0, buff.offset);
        return this;
    }
Appends another fast buffer to this one.