jodd-core/src/main/java/jodd/buffer/FastDoubleBuffer.java
public FastDoubleBuffer append(final FastDoubleBuffer buff) {
		if (buff.offset == 0) {
			return this;
		}
		append(buff.buffer, 0, buff.offset);
		return this;
	}
public FastDoubleBuffer append(final FastDoubleBuffer buff) {
		if (buff.offset == 0) {
			return this;
		}
		append(buff.buffer, 0, buff.offset);
		return this;
	}
Appends another fast buffer to this one.