best_split_function_from_gain_function: Get a best_split_function from a gain_function
In mlondschien/hdcd: High - Dimensional Change Point Detection

Get a best_split_function from a gain_function

1	best_split_function_from_gain_function(gain_function, optimizer, control)

`gain_function`	A function with argiument `x`, `start`, `end`, `lambda`, `control` that returns a closure with arguments split_point and possibly split_candidates that returns the gain after splitting the segment (`start`, `end`] at `split_point` given data `x` and tuning parameter `lambda`.
`optimizer`	Optimization method to be used to find an (approximate) of the maximum of the gain function. One of `line_search` for BS or similar, `section_search` for OBS or similar or `two_step_search`.
`control`	Control parameter as returned by hdcd_control

A function with formal arguments x, start, end, split_candidates and lambda that uses the optimizer specified to search for a maximum of the gain_function on the split_candidates given a segment (start, end], data x and a tuning parameter lambda and returns a list with arguments gain, max_gain, best_split and possible permutation_test and pval.