class RuboCop::Cop::Performance::FlatMap

def autocorrect(node)
  map_node, _first_method, _flatten, params = flat_map_candidate?(node)
  flatten_level, = *params.first
  return unless flatten_level
  range = range_between(node.loc.dot.begin_pos,
                        node.source_range.end_pos)
  lambda do |corrector|
    corrector.remove(range)
    corrector.replace(map_node.loc.selector, 'flat_map')
  end
end