class RuboCop::Cop::Style::MixinGrouping

def range_to_remove_for_subsequent_mixin(mixins, node)
  range = node.loc.expression
  prev_mixin = mixins.each_cons(2) { |m, n| break m if n == node }
  between = prev_mixin.loc.expression.end.join(range.begin)
  # if separated from previous mixin with only whitespace?
  unless /\S/.match?(between.source)
    range = range.join(between) # then remove that too
  end
  range
end