public ExternalLocation replaceExternalLocation(ExternalLocation toExternalLocation,
			ExternalLocation fromExternalLocation, ProgramMerge programMerge, TaskMonitor monitor)
			throws DuplicateNameException, InvalidInputException, CancelledException {

		// Change the namespace.
		replaceNamespace(toExternalLocation, fromExternalLocation, monitor);

		// Change the label, address and source.
		replaceLocation(toExternalLocation, fromExternalLocation, monitor);

		// TODO: replacing data type on a function seems wrong.  Do we handle the case
		// where we replace a function with a non-function?  

		// Replace the data type.
		replaceExternalDataType(toExternalLocation, fromExternalLocation, monitor);

		// Replace the function.
		return replaceFunction(toExternalLocation, fromExternalLocation, programMerge, monitor);
	}
Gets the external locations (result, latest, my, original) for the specified MY program
external space address.<br>
NOTE: Be careful where you call this method from. It is intended to be used for external
location changes only (not for Adds). It gets the ORIGINAL based on MY and then LATEST and
RESULT based on the ORIGINAL.
@param myAddress the MY program external space address for MY external location
@return all four program's external locations.
Ghidra/Features/Base/src/main/java/ghidra/app/merge/listing/ExternalFunctionMerger.java