Of course, I can change the document. 
max_linesearch from 20 to 40. (can keep the code unchanged by changing the document)
delta from 0 to 1e-5.  (can keep the code unchanged by changing the document)
delta value be will essential if past > 0(BTW, the default value of past is 0)
However, orthantwise_end  should be > 0. (which means the code has to be changed) for this value.