code: def test_empty_matrix():
      no_users, no_items = (10, 100)
  
      train = sp.coo_matrix((no_users, no_items), dtype=np.int32)
  
      model = LightFM()
      model.fit_partial(train)
  
imports: import numpy
  import pytest
  import scipy.sparse
  from lightfm.lightfm import LightFM
label_desc: Use image node_id 1 for calling a global function with example usage: test_empty_matrix() without return types