private Address graphBlock(AttributedGraph graph, CodeBlock curBB,
			List<AttributedVertex> entries) throws CancelledException {

		Address[] startAddrs = curBB.getStartAddresses();

		if (startAddrs == null || startAddrs.length == 0) {
			Msg.error(this, "Block not graphed, missing start address: " + curBB.getMinAddress());
			return null;
		}

		AttributedVertex vertex = graphBasicBlock(graph, curBB);

		if (graphEntryPointNexus && hasExternalEntryPoint(startAddrs)) {
			entries.add(vertex);
		}
		return startAddrs[0];
	}
Set the maximum number of code lines which will be used per block when
showCode is enabled.
@param maxLines maximum number of code lines
Ghidra/Features/ProgramGraph/src/main/java/ghidra/graph/program/BlockGraphTask.java