def host_errors(self, hostname, details):
if not hostname or not isinstance(hostname, basestring):<EOL><INDENT>return "<STR_LIT>"<EOL><DEDENT>if not isinstance(details, list):<EOL><INDENT>return "<STR_LIT>"<EOL><DEDENT>if len(details) != <NUM_LIT:3>:<EOL><INDENT>return "<STR_LIT>"<EOL><DEDENT>if details[<NUM_LIT:0>] not in self.balancer.action_mapping:<EOL><INDENT>return "<STR_LIT>" % details[<NUM_LIT:0>]<EOL><DEDENT>if not isinstance(details[<NUM_LIT:1>], dict):<EOL><INDENT>return "<STR_LIT>"<EOL><DEDENT>if not isinstance(details[<NUM_LIT:2>], bool):<EOL><INDENT>return "<STR_LIT>"<EOL><DEDENT>return None<EOL>
Validates the format of a host entry
Returns an error string, or None if it is valid.