@Override
	DBBuffer getBuffer(int bufferID) throws IOException {
		if (bufferID >= 0) {
			return handle.getBuffer(bufferID);
		}
		return null;
	}
MemoryMap adapter for version 3.
This version introduces the concept of sub memory blocks and FileBytes
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/mem/MemoryMapDBAdapterV3.java