class RuboCop::Cop::PercentLiteralCorrector

def process_lines(node, previous_line_num, base_line_num, source_in_lines)
  begin_line_num = previous_line_num - base_line_num + 1
  end_line_num = node.first_line - base_line_num + 1
  lines = source_in_lines[begin_line_num...end_line_num]
  "\n#{lines.join("\n").split(node.source).first || ''}"
end