@property<EOL><INDENT>def start(self):<DEDENT>
if self.order == '<STR_LIT>':<EOL><INDENT>return self[<NUM_LIT:0>].top<EOL><DEDENT>else:<EOL><INDENT>return self[-<NUM_LIT:1>].base<EOL><DEDENT>
Property. The closest Position to the datum.

Returns:
    Position.