sparse: use vfs.tryread()
vfs.exists() followed by a file read is an anti-pattern because it
incurs an extra stat() to test for file presence. vfs.tryread()
returns empty string on missing file and avoids the stat().
# name space package to host third party extensions
from __future__ import absolute_import
import pkgutil
__path__ = pkgutil.extend_path(__path__, __name__)