this lets you pass ruby keywords to templates:
<%= render 'example', class: "cool" %>
<%= render 'example', "spaces are" => "a-ok" %>
<%= render 'example', Foo: "bar" %>
Previously you'd see confusing syntax errors like this:
SyntaxError (.../_example.html.erb:1: syntax error, unexpected '='
Now you can reference invalid identifiers through local_assigns.
If you try to use an invalid keyword (e.g. class) in your template, you
get a syntax error on the line where you use it.
f9960f2d74