void join(MemoryBlockDB memBlock2) throws IOException {
		lastSubBlock = null;
		length += memBlock2.length;
		record.setLongValue(MemoryMapDBAdapter.LENGTH_COL, length);
		int n = subBlocks.size();
		subBlocks.addAll(memBlock2.subBlocks);
		possiblyMergeSubBlocks(n - 1, n);
		sequenceSubBlocks();
		adapter.deleteMemoryBlock(memBlock2);
		adapter.updateBlockRecord(record);

	}
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