@Override
	protected boolean join(SubMemoryBlock block) throws IOException {
		if (!(block instanceof BufferSubMemoryBlock)) {
			return false;
		}
		BufferSubMemoryBlock other = (BufferSubMemoryBlock) block;
		if (other.subBlockLength + subBlockLength > Memory.GBYTE) {
			return false;
		}
		buf.append(other.buf);
		setLength(subBlockLength + other.subBlockLength);
		adapter.deleteSubBlock(other.record.getKey());
		return true;
	}
Implementation of SubMemoryBlock for blocks that store bytes in their own private database
buffers
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/mem/BufferSubMemoryBlock.java