def scan(self, search_path=None):
if search_path is None:<EOL><INDENT>search_path = sys.path<EOL><DEDENT>for item in search_path:<EOL><INDENT>for dist in find_distributions(item):<EOL><INDENT>self.add(dist)<EOL><DEDENT><DEDENT>
Scan `search_path` for distributions usable in this environment

        Any distributions found are added to the environment.
        `search_path` should be a sequence of ``sys.path`` items.  If not
        supplied, ``sys.path`` is used.  Only distributions conforming to
        the platform/python version defined at initialization are added.