title: Stringify Keys Error
body: <p>Here is my method:</p>
  
  <pre><code>  def self.unique_coasters_this_year(year)
      counter = 0
      all.each do |c|
        years = new Array
        c.rode_on.each do |date, count|
          years &lt;&lt; (Date.parse date).year
        end
        if years.include?(year)
          counter += 1
        end
      end
      counter
    end
  </code></pre>
  
  <p>When running it I get this stringify_keys error:</p>
  
  <blockquote>
    <p>oMethodError: undefined method <code>stringify_keys' for Array:Class from
    /Users/user/.rbenv/versions/2.0.0-p0/lib/ruby/gems/2.0.0/gems/activerecord-3.2.12/lib/active_record/attribute_assignment.rb:69:in
    </code>assign_attributes' [97] pry(main)></p>
  </blockquote>
  
  <p>Any idea what is going wrong?</p>