Similar to the sample code for SDCA regression, we need samples for the binary classifiers:
SDCA
AveragedPerceptron
FastTree
LightGBM

There are two things to do, to resolve this issue:

1. Add a sample for each of the trainers in Microsoft.ML.Samples/Trainers.cs
   The samples can look similar to the cookbook example
   Download the adult dataset for the data to use.
   Take a look at the SDCA example, for reference.

2. Add a link to the xml documentation of SDCA
   AveragedPerceptron
   FastTree
   LightGBM
   to reference the new sample methods, like the one in SDCA has.