Data getDefinedDataAt(long addr) {
		if (addr == AddressMap.INVALID_ADDRESS_KEY) {
			return null;
		}
		lock.acquire();
		try {
			CodeUnit cu = cache.get(addr);
			if (cu == null) {
				DBRecord rec = dataAdapter.getRecord(addr);
				return getDataDB(rec);
			}
			else if (cu instanceof Data) {
				if (((Data) cu).isDefined()) {
					return (DataDB) cu;
				}
			}
		}
		catch (IOException e) {
			program.dbError(e);
		}
		finally {
			lock.release();
		}
		return null;
	}
Returns the defined data whose min address equals the specified address.

@param address the min address of the data defined to return 
@return the defined data at the specified address, or null if a defined data does 
not exist
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/code/CodeManager.java