title: Two models that depend on each other for instantiation
body: <p>I have two models that depend on each other how am I supposed to be able to create one without creating the other?</p>
  
  <pre><code>class Specification &lt; ActiveRecord::Base
    has_many :prices, inverse_of: :specification
    validates :prices, presence: true
  
  class Price &lt; ActiveRecord::Base
    belongs_to :specification, inverse_of: :prices
    validates :specification, presence: true
  </code></pre>