class RuboCop::Cop::Performance::RedundantSplitRegexpArgument

def on_send(node)
  return unless (regexp_node = split_call_with_regexp?(node))
  return if regexp_node.ignore_case? || regexp_node.content == ' '
  return unless determinist_regexp?(regexp_node)
  add_offense(regexp_node) do |corrector|
    new_argument = replacement(regexp_node)
    corrector.replace(regexp_node, "\"#{new_argument}\"")
  end
end