@property<EOL><INDENT>def is_tail(self):<EOL><DEDENT>
return self.current_index == <NUM_LIT:0><EOL>
Returns whether this transaction is a tail (first one in the
bundle).

Because of the way the Tangle is organized, the tail transaction
is generally the last one in the bundle that gets attached, even
though it occupies the first logical position inside the bundle.