createAsyncChunk(compilation, asyncOption, targetChunk) {
		const asyncChunk = compilation.addChunk(typeof asyncOption === "string" ? asyncOption : undefined);
		asyncChunk.chunkReason = "async commons chunk";
		asyncChunk.extraAsync = true;
		asyncChunk.addParent(targetChunk);
		targetChunk.addChunk(asyncChunk);
		return asyncChunk;
	}
If we find a "targetchunk" that is also a normal chunk (meaning it is probably specified as an entry)
and the current target chunk comes after that and the found chunk has a runtime*
make that chunk be an 'affected' chunk of the current target chunk.

To understand what that means take a look at the "examples/chunkhash", this basically will
result in the runtime to be extracted to the current target chunk.

*runtime: the "runtime" is the "webpack"-block you may have seen in the bundles that resolves modules etc.