protected boolean containsKey(Field encoded) {
		try {
			return store.table.hasRecord(encoded, columnIndex);
		}
		catch (IOException e) {
			store.dbError(e);
			return false;
		}
	}
Check if this index is empty

<p>
Except for sub-ranged indexes, this is equivalent to checking if the object store is empty.
For sub-ranged indexes, this checks if the store contains any object whose value for the
indexed field falls within the restricted range.

@return true if empty
Ghidra/Debug/ProposedUtils/src/main/java/ghidra/util/database/DBCachedObjectIndex.java