spec.unit.deep_preloader_spec
  ✅ DeepPreloader can parse a hash spec
  ❌ DeepPreloader can merge specs
	Failure/Error: association_specs[k].merge!(v)
  ✅ DeepPreloader with a test model can parse a polymorphic hash spec
  ✅ DeepPreloader with a one-to-one relationship in the belongs_to direction is not already loaded
  ✅ DeepPreloader with a one-to-one relationship in the belongs_to direction loads the child
  ✅ DeepPreloader with a one-to-one relationship in the belongs_to direction sets up the inverse relationship
  ✅ DeepPreloader with a one-to-one relationship in the belongs_to direction satisfies a childless parent
  ✅ DeepPreloader with a one-to-one relationship in the belongs_to direction loads more than one entity
  ✅ DeepPreloader with a one-to-one relationship in the belongs_to direction uses preloaded children from other parents before hitting the database
  ✅ DeepPreloader with a one-to-one relationship in the belongs_to direction supports locking
  ✅ DeepPreloader with a one-to-one relationship in the has_one direction loads the parent
  ✅ DeepPreloader with a one-to-one relationship in the has_one direction sets up the inverse relationship
  ✅ DeepPreloader with a one-to-one relationship in the has_one direction satisfies a parentless child
  ✅ DeepPreloader with a one-to-one relationship in the has_one direction loads more than one entity
  ✅ DeepPreloader with a one-to-one relationship in the has_one direction handles a preloaded child
  ✅ DeepPreloader with multiple belongs_to relationships with distinct children loads multiple relationships at once
  ✅ DeepPreloader with multiple belongs_to relationships with a diamond loads the same child for all three
  ✅ DeepPreloader with a has_many relationship loads the child
  ✅ DeepPreloader with a has_many relationship sets up the inverse relationship
  ✅ DeepPreloader with a has_many relationship satisfies a childless parent
  ✅ DeepPreloader with a has_many relationship handles preloaded children
  ✅ DeepPreloader with a has_many STI relationship loads the children
  ✅ DeepPreloader with a has_many STI relationship loads polymorphically through the children
  ✅ DeepPreloader with a polymorphic relationship loads different child types
  ✅ DeepPreloader with a polymorphic relationship sets the inverse associations
  ✅ DeepPreloader with a polymorphic relationship separates parent context when loading backwards
  ✅ DeepPreloader with a polymorphic relationship satisfies a childless parent
  ✅ DeepPreloader with a polymorphic relationship with grandchildren loads sub-specs through the polymorphic association