# File lib/rubypants.rb, line 235
  def educate(str, patt, repl, prevent_breaks)
    patt = /(?<spaces>[[:space:]]*)#{patt}/
    str.gsub(patt) do
      spaces = if prevent_breaks && $~['spaces'].length > 0
                 entity(:non_breaking_space) # * $~['spaces'].length
               elsif prevent_breaks
                 entity(:word_joiner)
               else
                 $~['spaces']
               end
      spaces + repl
    end
  end