code: def approxeq(a, b):
      return (a - b) <= ((a + b) * 1e-6)
  
file_path: pyqtgraph/tests/exporters/test_csv.py
imports: import csv
  import tempfile
  import numpy
  import pytest
  import pyqtgraph
label_desc: Use image node_id 1 for calling a global function with example usage: approxeq(a, b) and returns: unknown