:param: reg: To enable or disable regularization. Set to positive integer (greater than zero) to enable and to 0 to disable.
:param: mini_batch_size: Specifies the number of training samples taken in each step of Mini-Batch Gradient Descent. Will only be used if using ``LogisticRegression::MINI_BATCH`` training algorithm.
:param: mini_batch_size: Specifies the number of training samples taken in each step of Mini-Batch Gradient Descent. Will only be used if using ``LogisticRegression::MINI_BATCH`` training algorithm. It has to take values less than the total number of training samples.
The full constructor initializes corresponding members. The default constructor creates an object with dummy parameters.
