@Override
	public String getFieldName() {
		return null;
	}
Database implementation for the Data interface.

NOTE!! DataComponents only have a unique key within its parent Struct/Array.  This places a constraint on
the use of the key field and getKey() method on the underlying classes CodeUnitDB and DataDB.
The CodeUnit key should only be used for managing an object cache.  The addr field should be used within
this class instead of the key field which represents an "index in parent" for data components which are
cached separately.
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/code/DataDB.java