@Override
	public void setFallThrough(Address fallThroughAddr) {
		lock.acquire();
		try {
			checkDeleted();
			Address defaultFallThrough = proto.getFallThrough(this);
			if (addrsEqual(fallThroughAddr, defaultFallThrough)) {
				clearFallThroughOverride();
				return;
			}
			if (fallThroughAddr == null) {
				// Fall-through eliminated (i.e., terminal flow) - no reference added
				clearFallThroughRefs(null);
				setFallthroughOverride(true);
			}
			else {
				// Adding fallthough ref will trigger override flag on callback
				refMgr.addMemoryReference(address, fallThroughAddr, RefType.FALL_THROUGH,
					SourceType.USER_DEFINED, Reference.MNEMONIC);
			}
		}
		finally {
			lock.release();
		}
	}
Clear all existing fall-through references from address.
@param keepFallThroughAddr if not null, corresponding fall-through reference will be 
preserved.
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/code/InstructionDB.java