protected boolean expandBlock() {

		ExpandBlockCmd cmd = new ExpandBlockCmd(block);
		if (!tool.execute(cmd, program)) {
			message = cmd.getStatusMsg();
			tool.setStatusInfo(message);
			return false;
		}
		return true;
	}
Expand the given block; creates a new block at startAddr of
length, then joins the two blocks.
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/memory/ExpandBlockModel.java