def _acquire(<EOL>self,<EOL>url,<EOL>lock_type,<EOL>lock_scope,<EOL>lock_depth,<EOL>lock_owner,<EOL>timeout,<EOL>principal,<EOL>token_list,<EOL>):
try:<EOL><INDENT>return self.lm.acquire(<EOL>url,<EOL>lock_type,<EOL>lock_scope,<EOL>lock_depth,<EOL>lock_owner,<EOL>timeout,<EOL>principal,<EOL>token_list,<EOL>)<EOL><DEDENT>except DAVError:<EOL><INDENT>return None<EOL><DEDENT>
Wrapper for lm.acquire, that returns None instead of raising DAVError.