How to use the cfgrib.FileStream function in cfgrib

def test_reanalysis_Stream(test_file):
    dataset, request, key_count = TEST_FILES[test_file]
    path = cdscommon.ensure_data(dataset, request, name='cds-' + test_file + '-{uuid}.grib')

    stream = cfgrib.FileStream(path)
    leader = stream.first()
    assert len(leader) == key_count
    assert sum(1 for _ in stream) == leader['count']

def test_reanalysis_Stream(test_file):
    dataset, request, key_count = TEST_FILES[test_file]
    path = cdscommon.ensure_data(dataset, request, name=test_file + '{ext}')

    stream = cfgrib.FileStream(path)
    leader = stream.first()
    assert len(leader) == key_count
    assert sum(1 for _ in stream) == leader['count']

def test_reanalysis_Stream(test_file):
    dataset, request, key_count = TEST_FILES[test_file]
    path = cdscommon.ensure_data(dataset, request, name='cds-' + test_file + '-{uuid}.grib')

    stream = cfgrib.FileStream(path)
    leader = stream.first()
    assert len(leader) == key_count
    assert sum(1 for _ in stream) == leader['count']

def test_Stream(test_file):
    dataset, request, key_count = TEST_FILES[test_file]
    path = cdscommon.ensure_data(dataset, request, name='cds-' + test_file + '-{uuid}.grib')

    stream = cfgrib.FileStream(path)
    leader = stream.first()
    assert len(leader) == key_count
    assert sum(1 for _ in stream) == leader['count']

def test_Stream(test_file):
    dataset, request, key_count = TEST_FILES[test_file]
    path = cdscommon.ensure_data(dataset, request, name='cds-' + test_file + '-{uuid}.grib')

    stream = cfgrib.FileStream(path)
    leader = stream.first()
    assert len(leader) == key_count
    assert sum(1 for _ in stream) == leader['count']