async def METHOD_NAME(gs_filesystem):
    _, fs, base = gs_filesystem
    await fs.write(base + '?', b'contents of ?')
    assert await fs.read(base + '?') == b'contents of ?'
    await fs.write(base + '?a', b'contents of ?a')
    assert await fs.read(base + '?a') == b'contents of ?a'
    await fs.write(base + '?a#b', b'contents of ?a#b')
    assert await fs.read(base + '?a#b') == b'contents of ?a#b'
    await fs.write(base + '#b?a', b'contents of #b?a')
    assert await fs.read(base + '#b?a') == b'contents of #b?a'
    await fs.write(base + '?a#b@c', b'contents of ?a#b@c')
    assert await fs.read(base + '?a#b@c') == b'contents of ?a#b@c'
    await fs.write(base + '#b', b'contents of #b')
    assert await fs.read(base + '#b') == b'contents of #b'
    await fs.write(base + '???', b'contents of ???')
    assert await fs.read(base + '???') == b'contents of ???'