Importing sdlxliff

Hi, Im trying to expand a import tool we have so it also handles sdlxliff but Im having problems with something should be simple.

The SDK states that the TranslationMemoryImporter.FileTypeManager  must be set when importing bilingual documents, im trying to use:

importer.GetDefaultFileTypeManager() to set the importer.FileTypeManager (hoping it would grab all default filetypes and select the correct one based on the sdlxliff), but that throws "The context name passed to the GetContext method cannot be null or empty.".

Im thinking maybe GetDefaultFileTypeManager() does not do what I think (a description is missing in the docs) so I should maybe start implementing IFileTypeManager but before I continue with that Id like to know if im missing something obvious as this should just be setting the fieldtype I want to use.