DBBuffer getBuffer() {
		if (subBlocks.size() > 1) {
			throw new IllegalStateException(
				"Old blocks to be upgraded should only have one sub block");
		}
		SubMemoryBlock subMemoryBlock = subBlocks.get(0);
		if (subMemoryBlock instanceof BufferSubMemoryBlock) {
			return ((BufferSubMemoryBlock) subMemoryBlock).buf;
		}
		throw new IllegalStateException("Old blocks to be upgraded not expected type");

	}
Get collection of blocks which map onto this block.

@return collection of blocks which map onto this block or null if none identified
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/mem/MemoryBlockDB.java