private String matchHistory(String input) {
		if (setSelectedFlag) {
			return null;
		}
		if (input == null) {
			return null;
		}
		int count = getItemCount();
		for (int i = 0; i < count; i++) {
			String cur = getItemAt(i).toString();
			if (cur.startsWith(input)) {
				return cur;
			}
		}
		return null;
	}
This enables or disables auto completion. When on, the combobox will attempt to auto-fill
the input text box with drop-down items that start with the text entered. This behavior
may not be desirable when the drop-down list is more than just a list of previously typed
strings. Auto completion is on by default.
@param enable if true, auto completion is on, otherwise it is off.
Ghidra/Framework/Docking/src/main/java/docking/widgets/combobox/GhidraComboBox.java