class_docstr: Test data conversion to libsvm and libffm inside LRModel, FMModel and FFMModel
code: def setUp(self):
      # data generation
      self.num_rows = 10
      self.num_features = 4
      self.X = np.random.randn(self.num_rows, self.num_features)
      self.X[self.X < 0] = 0  # introduce sparsity
      self.y = np.random.binomial(1, 0.5, size=(self.num_rows, 1))
      self.fields = np.array([1, 2, 1, 0])
  
file_path: xlearn/python-package/test/test_data_conversion.py
imports: import unittest
  import tempfile
  import os
  import numpy
  from xlearn import write_data_to_xlearn_format
  from scipy.sparse import csr_matrix
  from sklearn.datasets import load_svmlight_file
label_desc: Use image node_id 1 for calling the TestDataConversion obj's underlying member method code with example usage: obj.setUp() without return types