@Override
	public void deleteAddressRange(Address startAddr, Address endAddr, TaskMonitor monitor)
			throws CancelledException {
		AddressRange.checkValidRange(startAddr, endAddr);
		lock.acquire();
		try {
			invalidateCache(true);
			Set<Address> notDeletedSet = adapter.deleteAddressRange(startAddr, endAddr, monitor);
			historyAdapter.deleteAddressRange(startAddr, endAddr, addrMap, notDeletedSet, monitor);
		}
		catch (IOException e) {
			program.dbError(e);
		}
		finally {
			lock.release();
		}
	}
Checks if the givens symbols from the same address have exactly one primary symbol amongst
them

@param symbols the array of symbols at a an address
@return true if there is exactly one primary symbol at the address (also true if no symbols
        at address)
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/symbol/SymbolManager.java