@Override
	public ExternalLocation getUniqueExternalLocation(String libraryName, String label) {
		Library library = getLibraryScope(libraryName);
		if (library == null && !StringUtils.isBlank(libraryName)) {
			return null;
		}
		return getUniqueExternalLocation(library, label);
	}
Get the external location which best matches the specified parameters.
Preference is given to extLabel over extAddr
@param library the library namespace containing this external location.
@param extLabel the name of the external location. Can be null.
@param extAddr the address of function in the external program.  Can be null
@return the best matching ExternalLocation or null.
@throws InvalidInputException if the extLabel name contains illegal characters (i.e. space)
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/external/ExternalManagerDB.java