code: def nan_dist(a: np.ndarray, b: np.ndarray):
      a[0] = np.nan
      a[1] = np.inf
      return 0, a
  
file_path: umap/umap/tests/test_data_input.py
imports: import numpy
  import pytest
  from numba import njit
  from umap import UMAP
label_desc: Use image node_id 3 for calling a global function with example usage: nan_dist(a, b) and returns: int,  a