invest/tests/test_datastack_modules/nonspatial_files.py

from natcap.invest import spec

MODEL_SPEC = spec.ModelSpec(inputs=[
    spec.FileInput(id='some_file'),
    spec.DirectoryInput(
        id='data_dir',
        contents=[])],
    outputs={},
    model_id='nonspatial_model',
    model_title='',
    userguide='',
    input_field_order=[]
)