code: def test_isfileobj():
      with tempdir(prefix="numpy_test_compat_") as folder:
          filename = join(folder, "a.bin")
  
          with open(filename, "wb") as f:
              assert_(isfileobj(f))
  
          with open(filename, "ab") as f:
              assert_(isfileobj(f))
  
          with open(filename, "rb") as f:
              assert_(isfileobj(f))
  
          assert_(isfileobj(BufferedReader(BytesIO())) is False)
  
imports: from os.path import join
  from io import BufferedReader, BytesIO
  from numpy.compat import isfileobj
  from numpy.testing import assert_
  from numpy.testing import tempdir
label_desc: Use image node_id 1 for calling a global function with example usage: test_isfileobj() without return types