@Override
	public Reference getPrimaryReferenceFrom(Address addr, int opIndex) {
		lock.acquire();
		try {
			RefList fromRefs = getFromRefs(addr);
			if (fromRefs != null) {
				return fromRefs.getPrimaryRef(opIndex);
			}
		}
		catch (IOException e) {
			program.dbError(e);
		}
		finally {
			lock.release();
		}
		return null;
	}
Get all memory references with the given from address at opIndex.
@param fromAddr the from address
@param opIndex the operand index
@return the references
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/references/ReferenceDBManager.java