def estimate_size(self):
<EOL>outs = len(self.outs) or <NUM_LIT:1><EOL>return outs * <NUM_LIT> + <NUM_LIT> * len(self.ins) + <NUM_LIT:10><EOL>
Estimate how many bytes this transaction will be by countng inputs
and outputs.
Formula taken from: http://bitcoin.stackexchange.com/a/3011/18150