void removeAllFrom(Address fromAddr) throws IOException {
		lock.acquire();
		try {
			RefList fromRefs = getFromRefs(fromAddr);
			if (fromRefs == null) {
				return;
			}
			Reference[] refs = fromRefs.getAllRefs();
			for (Reference ref : refs) {
				RefList toRefs = getToRefs(ref.getToAddress());
				if (toRefs != null) { // cope with buggy situation
					toRefs.removeRef(fromAddr, ref.getOperandIndex());
					if (toRefs.isEmpty()) {
						toCache.delete(toRefs.getKey());
					}
				}
				referenceRemoved(ref);
			}
			fromRefs.removeAll();
			fromCache.delete(fromRefs.getKey());
		}
		finally {
			lock.release();
		}
	}
Removes the external entry point at the given address
@param addr that address at which to remove the external entry point attribute.
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/references/ReferenceDBManager.java