def sanitize_code_blocks(text)
      text.gsub(/<pre>(.+?)<\/pre>/m) do
        code = $1.sub(/^\s*\n/, '')
        indent = code.gsub(/\n[ \t]*\n/, "\n").scan(/^ */).map{ |i| i.size }.min
        code.gsub!(/^#{' ' * indent}/, '') if indent > 0
        
        "<pre>#{code}</pre>"
      end
    end
def sanitize_code_blocks(text)
      text.gsub(/<pre>(.+?)<\/pre>/m) do
        code = $1.sub(/^\s*\n/, '')
        indent = code.gsub(/\n[ \t]*\n/, "\n").scan(/^ */).map{ |i| i.size }.min
        code.gsub!(/^#{' ' * indent}/, '') if indent > 0
        
        "<pre>#{code}</pre>"
      end
    end
primarily for removing leading whitespace in <pre> tags